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.
I’m right there with you. At the end of the day, there are hardly any games that are FOSS, and most of the greatest games are non-free, so you have to swallow that pill either way. Might as well at least do it from the most free OS you can.