This is why software is slow and everything uses 2GB of RAM at idle: because nobody really cares.

I'm sure that AI made this speedup work much easier and quicker; probably just access to the monorepo and a prompt of "make the launcher boot up faster while changing no functionality. Keep track of before/after benchmark numbers" would be fine as long as you can get your co-workers to approve whatever diff gets spat out the end.

But either of these companies, presumably with dev teams of dozens-hundreds of SWEs, could have pointed to one of them 5 years go and said "spend the next 2 months optimizing the performance of the launcher" and would probably have gotten similar results.

I make my software fast and efficient mostly because I enjoy it. Absolutely nothing stopping web apps, Electron, everything else from being efficient, slim, and performant. It's just that the modicum of effort required to set that up was outweighed by the convenience of just importing and parsing the full 16MB icon cache and 13 unused analytics SDKs every pageload and not worrying about it.