It’s not just performance but also quality. There are a ton of things which you get out of a native app which Electron developers who aren’t the VSC team never do. It’s almost always obvious who cared about UX more than portability, but the cost differential usually wins out.

Theoretically AI could help with this by making it easier to support multiple interfaces for the same backend functionality but it would run into the challenge of measuring good taste. A good Mac app has lots of interactive aspects which you notice while using it, and would have to be non-trivial to express in ways which a bot could measure.