This is one of the reasons why I’m a super fan of the macOS global menubar.
It’s always present and cannot be hidden by app developers, and so there’s no reason to not populate it, and thus the menubar serves as a consistently available master index of the program’s functions. That alone makes it invaluable.
I’m extremely disappointed Ubuntu gave up on Unity. It had the same basic concept, and menus being searchable was so good. GNOME’s determined direction (Adwaita) is so dumb for anything but small, simple apps. Just hopelessly bad.
Mind you, app-defined command palettes can be better than a global one because they can provide more information and context and augment it with other widgets as appropriate. The best command palettes are not just a searchable version of the menu, they add more.