Eventually we reach some kind of local maximum for UI/UX. So much of these things are a function of the relative immaturity of the platforms. They're all also pretty low hanging fruit.

In some ways, this is happening at the moment with AI and LLMs. The tools available, how we prompt them, etc are all "UI/UX innovation" if you believe these things have a use.

If we have a huge platform shift in the future (LLMs, AR/VR, ???), we may start from zero and go through "inventing tabs" again until that platform becomes maximally optimised.