Are many games built with Electron ...? I know there are a few HTML5 games, crosscode was the first one I recall seeing that really pushed it. Aren't most small games Unity or Godot?

CrossCode is a marvel in that they had to build their own runtime: https://news.ycombinator.com/item?id=41155807

I think the most famous Electron game is Vampire Suvivors, but it has since been ported to Unity.