They have to abide by the rules of the universe that WE know of. The universe is unbelievably big but also unfathomably OLD, so I'm sure there's been plenty of time for a number of civilizations to reach a technological level vastly larger than ours. Our latest technological revolution started just a hundred years ago. Imagine what just 10,000 more years can do. I mean, we thought (and our math said so) that the speed of sound was a physical barrier just a _few_ years ago. (https://en.wikipedia.org/wiki/Prandtl%E2%80%93Glauert_singul...)