While I personally use Windows 11 with heavy modifications, my father switched to Bazzite (Linux). I'm thinking that's the most sensible solution for the future however I would welcome GOG to support Linux a little better. The only reason it's at all user-friendly to use Galaxy features on Linux is thanks to Heroic Games and its Comet plugin, projects created and maintained entirely by members of the community

Just a few things:

1) MS will still support WIndows 10 for 2 - 3 years via a paid subscription service (supposedly details incoming)

2) MS recently stated that Windows 11 will in fact work on most "unsupported hardware" but MS will not vouch for longterm security support for "unsupported hardware" running Windows 11

With that said...

I intend on using a Windows 11 desktop for internet and running most games and tasks offline on my Windows 10 PCs.

I'd love to drop MS altogether, but I haven't got the time or patience to fiddle with Linux... yet.

Meanwhile for those who like facts, W11 adoption was barely 35% last October (the slowest historical on record) rather than "most people since 2023"...

As for sticking with W10, just put Enterprise 22H2 LTSC on. Despite Microsoft's own gaslighting that it's some "special magical build just for ATM's & MRI scanners", it's literally exactly the same as any other build down to and including XBox services, Freesync, etc. The only difference is the update channel (10 years worth of "no feature updates, security fixes only" vs the 2-3 years of rolling wall of bloat W11 is currently infected with) the former of which is what most sane grown-ups have wanted normal consumer / business W10 to be all along.

I agree that things will not break overnight. However, I detect some possible Survivorship bias in the latter part of what you say. Running an OS that is not updated is more dangerous and you need to take precautions. Not everyone is able to do that. Ahaha! So you are looking for the Windows 10 Definitive Edition?

Now that is PC gaming done right. I am impressed by your dedication. I wish I was your neighbor.

You mean to say "all the spying things I was able to find and turn off"?
Espionage is a covert operation. If Microsoft really wanted to peek into what you do with your computer (and it continues to signal, to uncomfortable levels, that it does not respect your privacy nor your absolute control over over your machine), then it would be able to hide it really well.

Normally I agree but in that particular example, they literally went out of their way to be infected including disabling the (enabled by default) incoming firewall then moving it from behind typical router's NAT / secondary firewall to connecting it to the net "raw" (like an old analogue 56k modem). W11 would absolutely be infected in the same way under same conditions. A router with a half decent firewall / NAT would straight up block incoming port scans, etc, from ever reaching devices which is why someone literally "hacking" other years out of support devices (eg, smart TV's, Blu-Ray players, consoles, etc) rarely happens in practise.

The biggest security / privacy threats with that stuff (as with W11) is the malware baked into them, eg, voice recordings / video capture of "smart" devices with microphones / cameras (and W11 Recall) being uploaded are all "features" of the device itself. And there is no securing against that other than throwing them in the bin...

I had heard slightly different numbers but the same idea -- starting in late 2023 many, many users were rolling back to W10. This is what led MS to change the language on the W11 pages to be inclusive of most "unsupported hardware."

I think there's a possibility that MS completely scraps the 2025 W11 change-over (although I wouldn't put money on it!). Now, how many years would that change-over stay inactivated? If the W11 experience doesn't get better, could potentially be a long, long time. But then MS is MS and might still want lose market share! ;)

As to the larger question...

... I went through this a little over a year ago when I heard the change-over had a definitive date. That prompted me to buy a W11 machine (desktop) and to look for a W11 laptop for emergencies (I still haven't used them!). But... I plan on using my W10 machines for everything except online far into the future. And should this set-up become too chaotic or too much of a headache, I'll definitely start looking at the most user-friendly Linux experience.

That is the reason why I'm at odds with IPv6, because the ONLY thing that stands between the Green Net and the Red net are the firewall rules, running atop some custom-made OS on a custom-made device (IOW, little to no real-world testing and feedback). With IPv4 you had to have NAT, which auto-shielded everything unless it's configured to properly forward it, so you are fully isolated unless explicitly configured otherwise (and even then it hits ony device only). With IPv6, you are by default fully exposed and the router only blocks things depending on its configuration and software. Leave a stray "ALLOW ALL" in the firewall rules and -bang-, you're fully exposed, not only one machine being forwarded to, but the entirety of your LAN. And that's perfectly imaginable human error on the manufacturers side, even if it occurs due to some failed parsing and processing of user input, possibly just because the parser chokes on a machine name containing whitespaces or perfectly valid unicode characters. We don't need to go to chinese backdoors (hello Netgear!) for that, but we could, or course.
Apart from that, I'd not be able to connect NWN2 for MP over the internet.

Anyway, I'm currently considering to switch.... from W7 to W10.
Linux has come a long way, and I use it for everything, except gaming. Not even Galaxy has a native Linux client, and SWTOR is getting a MAC installer after all these years, but no Linux support. I think about triple-booting DraugerOS, but if not even Steam could make Linux a go-to choice for game development with it's steam deck...

But in the end... it's nowhere near the worst case, just another major PITA.

I'm looking for an OS that remains basically unchanged feature-wise for the lifespan of the computer while still getting security and bug fixes, but which allows me full control of when, how and even if to install said fixes individually. So, you know, regarding this latter part, like it used to be before Win 8, after the launch of which they also introduced the cumulative updates system on 7 as well, though even there it was at least separated into security and non-security.

I see that you deposit a lot of trust on your routers. I am using the device my ISP provided me, which I'm convinced to be the cheapest model they were able to get that matched their specification.
The configuration UI shows lots of fancy useless features but it does not allow me to forward a port range! I am not convinced their focus was well placed.
I may get another router behind this machine to create another road block in case of intrusion. Sadly, I don't have much knowledge or time for such a project done right.

I used Windows XP until 2021. That's when the mother board battery died and I just bought a new computer.

No real problems.

If anyone uses a RaspberryPi, you can have the Pi run as a filter, between your computers you care about and the internet.

This sounds like a Debian stable (5 years of support, + 5 extra years on a subset of software) or an Ubuntu LTS (5 years of support).

I don’t remember how it works exactly for Ubuntu, but I think it is similar to Debian: you get only security fixes (and critical bug fixes) for the full support duration of your OS version. Only by upgrading to a newer version you would get changes in features.

That last part is obviously not forced unto you: you upgrade your system to a new version if and when you want to.

I using windows 10 until I needed new PC. It come with windows 11 so I stuck with it. Most times I having to switch OS was due to new PC. If my old old PC had lasted I would still using 7.

And frankly, LTS should never be user facing. LTS is for mechanics shops where keeping an onsite tech would be prohibitively expensive.

More damningly though is Ubuntu taking a LTS and then making their own LTS, which Mint turns into their own LTS. Hope you enjoy the jungle that becomes!