I agree, but it's not that easy.
All UI's should be tab-able, but that's still a miserable experience for keyboard users. A keyboard-centric UI must provide instantly discoverable shortcuts. Possible methods:
- Put all elements on a grid so that they can be navigable with the keyboard. This is a significant restriction for the designer.
- Put keyboard shortcuts next to every button. It's not enough to put them in tooltips (*cough* Raycast). Common in games, but wastes space.
- Add a Command Palette. This is the easiest, but it requires mirroring every action, and is suboptimal when you have the same action for each item in a set.
When designing for technical users: all of the above please. But for average users it's less clear. I think there's still room for innovation, both on the software architecture and the UI side.