PAYDAY 2 came to Linux officially back in 2016 but as of today they've removed support for it, so it will no longer see updates on the Native Linux version.
It does, however, still work quite well with the Windows version via Steam Play Proton on desktop Linux and is Steam Deck Verified against the Windows version in Proton. So while it’s a loss of support for their Native build, it’s still fully playable on Linux.
I’m okay with that, I used to be against, but I’ve come to realize that the only way to break the chicken and egg problem is to bring people over to Linux. Once the market share is large enough native versions will be appealing, and we can (and should) start to be stricter about non-native versions, but at less than 2% of Steam we’re too small of a market share to be making demands, even if that means millions of users.
I’m okay with that, I used to be against, but I’ve come to realize that the only way to break the chicken and egg problem is to bring people over to Linux. Once the market share is large enough native versions will be appealing, and we can (and should) start to be stricter about non-native versions, but at less than 2% of Steam we’re too small of a market share to be making demands, even if that means millions of users.