There are plenty of new scientific results that in both Math and Machine Learning that are essentially 6 months/a few years/a few decades of hard work away from discovery.
As a professor once told me: IF you're lucky, after 10 years in academia, you get to be creative and come up with 4-5 ideas once every 5 years or so (when coming up with the suggested list of research for new phd students to do). Then you get to be devastated when no-one picks up any of your more creative ideas, and everyone picks the 10 non-creative ideas on the list because they don't want to risk their phd.
Yeah, so a person like Carmack who takes the risk and spent his career doing technically creative things could maybe make a difference. Probably not, but as long as creativity is so de-incentivized we will never have too many creative individuals around.
Even if those ideas are death ends its really important for the rest of the community to know at least some one has put some efforts and discovered several death branches in that creative direction.
As a professor once told me: IF you're lucky, after 10 years in academia, you get to be creative and come up with 4-5 ideas once every 5 years or so (when coming up with the suggested list of research for new phd students to do). Then you get to be devastated when no-one picks up any of your more creative ideas, and everyone picks the 10 non-creative ideas on the list because they don't want to risk their phd.