Possibilities:
1. You ride at max recommended pressure, but the tires deform while riding and you wear a crack in the sidewall for early failure, or you get more damage than you otherwise would from a pothole or curb jump.
2. You ride at higher than max recommended pressure, and the tires handle it fine, with somewhat increased chances of a blowout and possible bad consequences.

I think your objective ought to be finding the Goldilocks pressure, which would be the minimum amount above #1 that gives you an acceptable amount of tire flex. I propose you increase by 5psi for a dozen rides or so and keep good notes about how they look and feel. Then repeat with another 5psi and re-evaluate. 50psi is a pretty low max pressure rating, I'd feel safe with at least another 15, but go slowly with the changes.