Has it really been that long? Apparently so. Valve originally announced their rebranding of Steam Play with Proton back on August 21st, 2018. Seems like a good time for a quick reflection being halfway to a decade old now with the tech that gave rise to the Steam Deck.
Proton is based on wine, which is copyleft so valve didn’t exactly have a choice in keeping it open source. I also don’t necessarily think that their goal was to reach the rather small existing user base of Linux users, but rather they wanted to make sure they aren’t at the will of a bigger company (Microsoft) whose product is/was required to run most of what valve makes money with.
This is probably more accurate, their entire model depended on Windows, and if they wanted to make their own devices they would all be forced to either start new or get Linux up and running. Motives aside they did good for the community
Oh yeah their efforts are definitely a huge net benefit for the Linux community, I just don’t like seeing big companies portrayed in a better light than they deserve. When it comes down to it, what valve really cares about is still their bottom line.