The search bar is excellent and being keyboard driven fast too.
The ribbon is also entirely keyboard-drivable and fast that way. I’ve seen the data on why it was introduced; it was a scaling issue- the old toolbars simply could no longer fit all the functionality in apps like Excel, so they made them context-aware.
Importantly: The ribbon also makes the shortcut chords discoverable, so people can find shortcuts for the stuff they use often by themselves. It lets you get at tons of functions both as a first-timer discovering stuff visually, as well as a seasoned veteran with keyboard alone. There's some things they could polish a bit (colour pickers, mainly), but the system is overall really good.
The ribbon is also entirely keyboard-drivable and fast that way. I’ve seen the data on why it was introduced; it was a scaling issue- the old toolbars simply could no longer fit all the functionality in apps like Excel, so they made them context-aware.