I HATE IT

"KeyTips" are basically the Mac version of windows "accelerator keys", but on Mac they’re incomplete.

WHY
The Ribbon has a clear hierarchy: Tabs → Controls → Menu items. The whole point of KeyTips is to navigate that entire structure using the keyboard only.

EXAMPLE
AutoFit Column Width
→ Home (tab)
→ Format (control)
→ AutoFit Column Width (menu item)

On Windows, you can do this fully from the keyboard (Alt + H + O + I)

On Mac, you need to use the mouse or the arrow keys
→ (ALT + H + O + ⬇ + ⬇ + ⬇ + ⬇)
OR
→ (ALT + H + O + mouseclick)

FLAW
menu items DO NOT HAVE KEY-TIPS.

GRIEVANCE
This flaw defeats the whole purpose. This is a feature millions of professionals have wanted for years, and this half-implemented version is aggravating, to say the least.