While possible, the uptake/usage is very low once it requires lots of CTRL / ALT / CMD button sequences. Take something like Excel, which many users use daily for work, but most people likely only use less than a dozen common keyboard shortcuts. Practically nobody navigates the ribbon with their keyboard.

I'm in a role of Finance / Excel "super user" in my profession. There's a subculture of keyboard shortcut enthusiasts, but generally everyone is using their mouse a lot. I myself have about 20 that I use and rarely incorporate a new one into the mix, it has to be an action I perform repetitively for me to care enough to memorize seek out and learn the shortcut. I find navigating the ribbon usually requires too many keypresses and I instead have a custom quick access bar that I put everything I want access to so I don't have to toggle differing ribbons, I still use my mouse even though I know I could use my keyboard. It doesn't feel easier