Carmack has had a lot of commercial success, which is great and I value his creativity in the space but working on a research question that is about ten paradigm shifts away is a different task than putting in hard labour to build games.
And maybe the output is he helps bring about one of those ten paradigm shifts, which would be a wonderful success. He didn’t say “solve” it, he said work on it.
People with this level of track record should not be underestimated, there aren't many of them out there... They matter.