Frozenbyte being the developer behind titles like the Trine series, Shadwen, Has-Been Heroes and the upcoming Starbase talks a little about Proton and future native Linux support. If you're not clear on what Proton and Steam Play are, be sure to check out our constantly updated dedicated page. It's a special compatibility layer for running Windows games and apps from Steam on Linux.
If you're not aware, Frozenbyte did previously have their games ported over to Linux but they eventually stopped after the release of Shadwen in 2016. The latest Trine 4 and their other titles don't have Linux version. With Starbase that's due to release tomorrow (July 29, 2021), there's a post on the Steam forum from a user asking about Linux support and Frozenbyte developer Jukka Larja (JLarja) replied on July 27 to explain it's not a priority:
With Proton being as good as it is, native support is not very high on our list. In fact (without actually trying the native versions on modern Linux distro) I would recommend Proton emulation over native versions for all the previous games we've released. Changes are you'll get better graphics quality, likely less trouble getting the game running and input working, and possible better performance too. For low-on-resources port Proton is simply superior.
If Linux gaming takes off (for example, because Steam Deck becomes a huge success), then we'll have a reason to consider not-so-low-on-resources port, which may (and probably does) change the picture somewhat. At the moment we have Xbox Series X/S higher on our porting targets list though (not for Starbase currently, but for other future projects).
I imagine there will be plenty more of this, especially for older ports where performance wasn't top and some that might have other issues. Proton isn't just something that's good to ensure Linux gamers and Steam Deck users get to play the latest games, it's also (as even porter Ethan Lee has pointed out), good for being an "essential preservation project" for older Windows games to keep them working nicely.
What is interesting to see is a mention of it being possibility if the Steam Deck is a success. People will argue on one side about there not being a point if Proton gets to the stage where Windows games can just run out of the box on Linux with Proton, but there is the other side that a native Linux build gives developers more control and flexibility on their games compared with handing it all over to Valve. Either way, that and more depends on how the Steam Deck goes.