Wow, this is awful. Some people reported that these ads are also very petty and not necessarily related to the game, like apparently Elden Ring shows an ad for a licensed mousepad when you hover over the game now…
Edit: Playstation Product Manager says this is actually a new bug. I really doubt it but they do seem to be “fixing it”.
Look, if the choice is “use Ubuntu because it’s easy and officially supported by Steam” or "give up and stuck with Windows (or even worse, a console) would you really suggest the latter?