We put our human limitations on any possible aliens.
But if you don't mind spending a few generations getting to another
star system
Aliens could have 1,000, 10,000 or 100,000 year lifespans. The way they get energy could be different from us. What if they didn’t need to eat food like us- think plants.
They may also be able to hibernate better than humans. They could freeze themselves for the trip.
We shouldn’t impose our limitations on any possible aliens out there.