Earlier quoted context omitted.
I don't think Proton has prevented anything. In fact, without it, and the back catalog of Windows games it makes available on SteamDeck, I doubt the handheld would have been as popular. SteamDeck was successful enough to get a re-release in the form of the OLED model, which is a big success for a Linux handheld. The longer Valve remains committed to the platform, and the more devices they get into the hands of consum…
The people I mentioned in my comment clearly disagree with you, and frankly they have more of an incentive to be well informed about the situation. See the twitter link I posted to your comment's sibling for Ethan Lee's impressions from three years ago. Also, I never argued against Proton having been a boon for Linux gamers, but I tried to present an opposing point of view that usually does not get taken into account…
Without Proton the steam deck would not be popular enough to warrant any Linux ports either way. So Linux ports would be doomed regardless.
The real travesty is steam, with the recent introduction of WoW64 in Wine, is now the only software that requires me to run 32bit binaries on my desktop. Real annoying.