1) I don't tend to think of games as applications with GUIs, but you're right, they really are, and yes, they can be CPU-bound sometimes. However, a game that was actually CPU-bound would be very unpleasant to play. That's not true for the applications that run on super-computers: they just take longer to run that someone would like.

2) video conferencing is not CPU-bound unless you're doing 1-to-many/many-to-1 feeds locally.

3) JS heavy web browsing ... 'nuff said.

4) Very few people do video editing that is CPU bound. Certainly for video editors, it is an issue.

Clearly, I should have said:

  "The majority of applications used by the majority of users are rarely CPU-bound"

But more importantly: even the exceptions are really nothing like "supercomputer workloads".