Of course black holes come in different sizes but what about the density? Time after time we are told that a black hole contains a point mass of infinite density. Where is the proof of this? The only thing the astronomers can tell us is that there are objects out there denser than a neutron star. It follows from this that neutrons can be crushed into something smaller - but how small exactly?
Einstein's theory of general relativity PREDICTS that a sufficiently large mass will collapse to a single point but where is the proof???
PS: Mini black holes can, in theory, be formed at the temperatures achieved in a hydrogen bomb explosion. Nobody thought of that when they tested the first one.