On MacOS is much better. But most of the team either ended up with locked in Mac-only or go cross platform with Electron.
You don't need to use microsoft's or apple's or google's shit UI frameworks. E.g. see https://filepilot.tech/
You can just write all the rendering yourself using metal/gl/dx. if you didn't want to write the rendering yourself there are plenty of libraries like skia, flutter's renderer, nanovg, etc
You will be outcompeted if you waste your time reinventing the wheel and optimizing for stuff that doesn't matter. There is some market for highly optimized apps like e.g. Sublime Text, but you can clearly see that the companies behind them are struggling.
There's plenty of competition for VSCode too.
Don't forget that these Electron apps outcompeted native apps. Figma and VSCode were underdogs to native apps at one point. This is why your supply side argument doesn't make any sense.
But there isn't, not if you include all the extensions and remember the price
If it was a hindrance, why did it win?
Seems clear to me that Electron's higher RAM usage did not affect adoption. Instead, Electron's ability to write once and ship in any platform is what allowed VSCode to win.