Source is this video:
Windows Was The Problem All Along - Dave2D
We could obviously compare performance between windows and steamOS before on the steam deck, or between windows and Bazzite on other handhelds. But this is the first time we have had official windows and SteamOS builds for the same hardware.
Except these tests were almost certainly being run on SteamOS using WINE with Proton. We can’t know what the numbers would be with any other setup without doing it. Would a Protonless DXVK for WINE run just as well? We can’t know from these figure.
Also, Proton does not require running through Steam. I play Epic, GoG, and otherwise sources games with Proton not through Steam all the time. It’s also more than just DXVK. That’s a big part of it though.
No one is arguing that DXVK isn’t important or anything like that. They’re just saying Proton is a piece of this, which includes DXVK. I don’t know why you’re arguing.