I said, Linux is great for gaming!

Just wanted to make sure you heard that.

that will be
10 Leviticus 19:11 NIV prayers

The computer I'm using on my BatCave is based on a old Phenom 960t, unlocked to 6 cores, is amazing what a 10+ computer can still play. At the moment I'm stuck with the integrated motherboard graphics but even so, can play a lot of interesting games (Into the Breach, Battle Brothers, Fell Seal etc) and have some video acceleration for browsing and youtube.
With the previous HD 6950 (that came with the computer) could play Shadow Tactics all day long at 100+ fps...

Have also a few core2duo and core2quad around, the quads are also usable when coupled with a graphic card (the integrated graphics can't do jack s*** nowadays).
Actually a Core2quad is a very cheap way to anyone get a desktop computer, they are available used for peanuts and the quad CPU's are available on ebay for 6 Euros to upgrade any duo processor. A bit of duct tape can overclock the Q6600 to 3GHz, great for any retro pc with "modern-ish" functionality, like decent web browsing.

All in all, who'd say in 2010 that you could still play a lot of modern games in 2020+.
https://row1.ca/images/on/stick-poking.png

I have a bunch of PlayStations 1,2 and 3 and a bunch of Wii's and a bunch of Xbox's and Xbox 360 and a couple of decade old pc's, nothing really retro though.

I'm in the process of modding a few of my consoles but only managed to repair and mod a Playstation 2 so far.
But honestly I wished emulation would catch up, escpecially Windows 95/98 and Xbox, Xbox 360 and PS3.

My PS2 is also modded so that I could install a hard drive into it, and install (at least most of) my PS2 games to its hard drive, and run them from there, instead of having to swap CDs or DVDs in the tray all the time. It worked (works, I guess) quite well, but as said, I am more into PCSX2 emulation nowadays.

I am not that interested in newer generation (PS3, PS4, XBox360, XboxOne...) emulation because I feel most of their games are generic cross-platform games, for the most part. So if I want to play some Call of Duty or whatever, why not just try to play the PC version then. Even said consoles, especially XBox, genres seem to be quite similar to PC game genres.

On earlier console generations (PS2 and Playstation), the console games and their genres differed much more from PC games, so that is why I find it more interesting to try to emulate them. And then there are of course the Nintendo consoles, N64, Gamecube etc., they certainly have kinds of games you don't generally see, or at least saw, on PC.

Another thing is, don't those newer consoles usually have quite advanced gamepads with odd functionalities that are not necessarily recreated on PC gamepads? I recall that already on the PS2 gamepad, some of the face buttons were actually analog (ie. it mattered how strongly you pushed them), and that was not the case with equivalent PC gamepads? (Or then I remember that wrong... but I recall the PS2 games like Metal Gear Solid 2 and/or 3 would have used that feature too?).

So I am wondering how such console emulators would be able to emulate such advanced hardware (gamepad) functionalities? And now PS5 has some weird haptic feedback blaa blaa in its gamepads...

I guess that makes Nintendo Wii games pretty hard to emulate as well, as didn't it have those weird sticks you'd wave around in mid-air? I think I've seen a couple thousand videos of people destroying their living room lamps in the ceiling or their TV, while swinging around those "nunchaku-sticks"? Or at least hitting their kid to the mouth with them accidentally.

I figure it is quite hard to emulate those controllers with a mouse or a generic gamepad?

I still have my first computer, a 133mhz one. I bought a used 386 and 486 after that.
Also added to the list are my two next computers, a 450mhz and a 1.6ghz.
Maybe my current one counts as old too, but it suffices.

My PS2 has a harddrive as well and I want to do the same with one of my Xbox's and PS3 and Xbox 360, but it's harder to do.

Indeed a lot of PS3/Xbox 360 titles are cross platform and usually there is no reason to play them on a console unless you want cheap 2nd hand physical copies, which I want to get rid of because I don't want to be a collector anymore.
The main reason I have a PS3 and Xbox 360 is because of the Gran Turismo and Forza games.

Yes, there are console specific controller functions like the hardly used pressure sensitive buttons of the PS2 controller or Sixaxis motion control of the PS3. A trade-off with emulation could be made by using a console specific controller or use a tabled or smartphone for the more advanced functions.