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.
No, because going from thousands of games to play to even more that you will never have the time to play is not a quantum leap.
If you had said Proton/DXVK made it finally possible to play a few triple A games I would have agreed. Still not a quantum leap though.
Ah, good ole “your opinion is subjective, but mine is absolute”.