Brute force is powerful yes. And another way to look at math problems is that humans solved a huge lot of very hard math problems already but didn't solve all of them.

Another thing humans did is invent the telescope, the microscope, the transistor, antibiotics, the computer, AI, discovered how to send satellites in space and how to do heart-transplant etc.

I'd say there's still some way to go for AI before we declare humans dumb because they "failed for decades" at solving a few math problems.