Quoting: F.Ultra

Quoting: Lofty

Quoting: JowseyAt least it still works well with Proton, so nothing significant lost!

On the flip side we could look at it and say something is gained. Now that the steam deck is here and pretty much people are exclusively using proton to game on modern titles, the motivation to make their next game work on proton may be higher as it is not seen as a 'moving target' like Linux is often portrayed as by developers and it must be easier to test if their build works on proton.
Of course there is the issue with anti-cheat, but again given the success and popularity of the steam deck, hopefully they are now aware of this and make the adjustments necessary.

Quoting: DrMcCoy

but the ultimate reason is pretty much the same as always — Linux and Steam Deck together hold a less than 2% user share on Steam

Sorry, but no, that's wrong. The reason is this:

due to the Linux version being on an older version of the PAYDAY 2 engine

I.e. a terrible development environment, the developers being bad at their job.

That quote right there, that tells me that they kept the Linux codebase in a separate fork. That's bad praxis, that's objectively incompetent.

Forking the codebase to put in support for another platform is fundamentally wrong, and we see, time and time again, that this leads to the codebases growing apart with the developers not being able to keep up keeping them in sync, and then abandoning the other platform. 90% of the time were we had Linux support being wiped away was because of this very reason. Why aren't people learning? You don't do that.

Instead, you need to make portability a feature of your code outright, you need to make the same single codebase run on all the individual platforms. No forks, just one portable repository that can run everywhere. That's not new knowledge either, we've known that for decades!

While that is a terrible way to perform development it unfortunately is quite the norm. The studios do this with basically every single port, be it for the switch or ps5, which ultimately leads to them having several different versions of the same game instead of a single codebase where fixes for one platform means fixes for all. The reason of course is that it is initially much easier to do it this way, aka write your game for PS2 first then when it becomes popular send off the entire codebase to another company to port it to the Gamecube and once Gamecube is no longer a viable platform management can happily terminate that contract and the code is thrown in the can.