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.
13 year linux vet here, yes it was. Literally nothing worked without troubleshooting and dicking around with configs. Even running the windows version of Steam in WINE was hit or miss and was constantly plagued with issues. If it “was not that bad” nobody would of recommended running a Windows VM with GPU passthrough like they did back then.