I think any observation that imagines that old-school dropdown-menu-based applications are easier to use than iOS/Android applications is empirically off-base.

I think any observation that imagines that old-school dropdown-menu-based applications are easier to use than iOS/Android applications is empirically off-base. More people use, more fluently, phone apps than ever used those desktop ones. That's not to say that iOS-style interfaces are perfect -- obviously there are flaws there -- but if your starting premise is that MacOS was easier to use than iOS, you're just fundamentally at odds with reality, and need to figure out which of your premises are wrong.