Perhaps what happened is that game console demographics have changed so dramatically from a kids-only toy, to the preteen/teen male of the original Xbox era, and now to a general purpose entertainment device that has to appeal to all ages and demographics.

Probably the only console interface left with some whimsy is Nintendo but it is definitely a more muted and professional look than the past.

I’d also argue that Steam has had a very PC power user aesthetic for a long time, and while it isn’t quite as fun as any of these it’s definitely not corporate boring like PlayStation 5 or Xbox.