The limits of computers would be the same as the limits for humans. We have no reason to think the human brain has a stronger computation power than a Turing machine.

So, in a way, learning about the limits of computers is the exact same as learning the limits of humans.

But also, learning what the limits of computers are is absolutely relevant. You get asked to create an algorithm for a problem and its useful to be able to figure out whether it actually is solvable, or how fast it theoretically can be. Avoids wasting everyone's time trying to build an infinite loop detector.