The difference between rates increases as the observer’s spacetime gets more and more distorted, so the closer you get to the black hole the faster times moves outside the event horizon.

To the extent that from the singularity itself, the outside universe is equally stretched out to forever since all reference frames are equal, so outside a literal infinity passes… and no we don’t have any understanding what this means, only that it seems to exist like this and this is one of many problems we still have with our understanding of black holes.