The Observable Universe Might Be A Black Hole, Suggests A Chart Of Everything

The extent of my knowledge of astrophysics and relativity are around the size of the next comma in this sentence, but wouldn’t a great deal of time pass “inside” such a black hole such that a “universe” could rise and fall in what would seem to us as just a few microseconds due to relativistic effects?

Kind of leads Credence to the Buddhist idea that we are all already in hell and living multiple lives in hopes of refining ourselves enough to get out one day.