Or we could just be an atom inside a table
That's the idea of the multiverse. That this is not the only universe, There plenty of others. But the theories about the "Platform" that includes all these universes together have been unconvincing until now. A blackhole is suggested because we don't know what do black holes do to information. So, It's suggested that it might be universes all tied together somehow. The idea of the matrix is born of the same idea that you originally spoke of, That the universe may have been artificially created. But this time, The scenario is more plausible and have a real ground and basis. It has been explained thoroughly in the first Matrix movie which is considered to be one of the best movies of all times.
But, Want my personal guess? Neither of those are the answer. Some of them could be parts of the answer, But they're not the full answer. You see, Before, We thought the Sun spins around the Earth and that the Earth is the center of the universe and that the earth is flat and all these stuff only to find out that they were wrong. It's the same case with the Classical physics imagined explanation of the universe that the modern and quantum physicists, Including Einstein helped prove wrong. So, We're doing the same again, The same cycle, Making theories based on old theories and information instead of using our imagination to create new ones that would truly be able to explain the anomalies of the world. Einstein himself said that no theory would last forever. While i slightly disagree, It's true. Until we reach the theory of everything, No theory would or can be 100% true. Even Einstein's relativity is starting to get challenged nowadays.