Unfortunately, no. Maths is so vast that what might seem a trivial and silly brain teaser can turn out to unlock a massive problem in a seemingly completely unrelated subfield of mathematics, and we won't know until someone discovers that link.
What someone might call "a silly little brain teaser" today could actually result in a breakthrough paper weeks (or centuries) from now in a different subfield because someone far smarter than us realized that part of the problem they were working was actually analogous to a number theory related problem that was simplified, even a tiny bit, by this solution. (Hell, Nash built his entire career on spotting those kind of links and then telling other mathematicians to focus on working out the individual pieces)
Maths plays out over "we don't even know how long or short" time scales. What's the use? We don't know, it's probably completely useless. Until someone suddenly realizes that it's not.
What someone might call "a silly little brain teaser" today could actually result in a breakthrough paper weeks (or centuries) from now in a different subfield because someone far smarter than us realized that part of the problem they were working was actually analogous to a number theory related problem that was simplified, even a tiny bit, by this solution. (Hell, Nash built his entire career on spotting those kind of links and then telling other mathematicians to focus on working out the individual pieces)
Maths plays out over "we don't even know how long or short" time scales. What's the use? We don't know, it's probably completely useless. Until someone suddenly realizes that it's not.