Read my post again! I was differentiating between account-to-buy and account-to-play. The last one is the relevant DRM.
And yes, buying software without an account exists. (via personalised links)

If it ill happen that a game here on the site gog.com requires epic launcher you can have the
"TOLD YA SO" moment until then chill out.

You answered your own question. The move is completely antithetical to the concept of DRM-free. GOG is showing they don't care any more about the DRM-free cause and are more interested in facilitating customers buying games from another store to make a quick buck (to satisfy greedy Mr. Shareholder) than they are in promoting DRM-free and encouraging more players and developers to embrace it. It is a harsh slap in the face for anyone that values the concept of DRM-free games.

What is there to not understand?

Many bundle sites allow buying games without an account, so it's possible.

From a "verified GOG rep" on Reddit in response to the question "Does this mean that I can install and launch games from Epic without Epic Launcher?":

"No, the launcher is still necessary as these games have DRM. It means that, if you already have the Epic launcher installed, you can install the game without leaving the GOG GALAXY app. Otherwise when you were to install the game, it will ask you to install the launcher."

source: https://old.reddit.com/r/gog/comments/j35rry/new_store_inside_gog_galaxy_launches_in_test_phase/g7aevm9/

So it seems that the Epic Launcher will run in the background no matter what.

TO EVERYONE:

Download and back up your offline installers now! Don't wait, do it as soon as you can. The GOG ship is going down, slowly but surely, pulled under by greedy, anti-ethical corporate forces. Don't get caught wrong-footed.

A bit late for an April Fool's joke, don't you think?

Jokes aside, having to use the Galaxy client in the future to play your gog games doesn't sound so crazy now.
Sad times indeed. :/
Oh well, should that happen, I'll be fucking gone. :P
...
I mean, there have been quite a few signs that show gog not giving a fuck about a little DRM in the games they sell. :P

I think you're selling yourself short actually. We are a small niche but niche markets/businesses can succeed and in some cases have a better chance to succeed than entering a "red ocean" i.e. a saturated market.

We know that DRM-free is the USP of GOG. To detail that a little more, DRM-free offline installers of big releases are what are only consistently available on GOG, even when considering games available for purchase from other (smaller) DRM-free stores and the occasional Scheme release that can apparently run without clients (mind you, like Epic Fail Store, such games on Scheme are not advertised as such and can change to client requirements at any moment, which by the way has happened with games on both Scheme and Epic Fail Store already, but I digress). "Old games" is no longer the USP and in fact cannot be when other sites sell old games DRM-free. Without DRM-free offline installers of sufficiently significant releases, what is the incentive for a new customer to shop here versus other platforms?

In other words, what is the USP now? The client to end all clients? I'm not seeing how "a mega-client" is that unique from other clients especially when people don't seem to mind using the other clients all that much.

Wait just a moment, this is not exactly the Titanic hitting an iceberg. That being said, I already have backups of my offline installer backups (redundancy be praised), but I don't expect GOG to stop offering offline installers for the games they sell directly.

At least not... soon. Maybe eventually? It's hard to know what they're up to these days...

I'm still holding onto what skeletonbow said, that this might all be a joke in poor taste. Heck, at this point I'm hoping it is, against my better judgement.

GOG seems to be trying to transition from their USP "DRM-free" (which is their only selling point that is actually good) to "a curated selection of games" (which no one cares about, and in fact GOG curation has many opponents) and "one place to launch all your games from with Galaxy 2.0" (and like you said, no one cares about that either...especially not GOG customers who value DRM-free).

Everybody who cares about DRM free should do that - but not because of fear mongering.

When i see the news of epic launcher requirements on this site you also got
your "TOLD YA SO" moment. As it will be my last day here as i walk away like i did
with steam 10 years ago. What happens withing galaxy i don't care.

Well if you don't care what happen within Galaxy then this news doesn't change anything for you.

What in the actual fuck, GOG?