> Now, unfortunately, Apple is on a rigid yearly OS update schedule

I cannot think of anything that less needs yearly major updates than macOS. It's a mature, 25 year old OS that, unlike iOS, is used for an enormous range of professional work. I need to it be fast, stable, and predictable. The last thing I want is change for the sake of change, which largely describes the last 5-10 years of the OS.

Wanna make Notes.app compatible with the new features in this year's iOS? Just update Notes. I don't need a whole new OS to get new features for a notepad.