If you look at the developers of Proton, Lutris, and wine you will see a decent number of codeweavers employees. I think valve may have even hired them to develop the compatability layer on the steam deck (Proton/Wine).

It’s pretty normal for water blocks to come out well after a GPUs release. Also it looks like it was a new product/company so it makes sense the design took longer than the competition.

Actually the common anti cheat solutions provided Linux support for a while, but the developers/publishers have been choosing not to enable it.