Might not be a huge deal for current Linux users, because of Heroic and Lutris are well known and widely used, but for gamers who are about to switch from Windows this could be another reason to do so.

I saw many "how to switch to Linux" guides where they had to stop at the gaming section and explain Proton/Wine/Heroic/etc

It sounds much easier: If you want to game on Linux there is a native Steam and GoG clients.

Lots of people loves achievments and cloud saves.