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.