In article ,
Nicolaas Vroom writes:

You can *calculate* Hawking radiation, using what are now
standard methods of quantum field theory in a curved background.
The result is definitely not a pure state.

Again, it could be that this calculation is badly wrong. But,
again, the problem is to explain *why* it's wrong.

The first thing is to verify why your calculation is correct.
For example you have to very that the BH "emits" radiation.
and that the predicted energy range is correct.

If the calculation is correct, then the radiation is essentially
undetectable for all but the smallest black holes. So, while one could
verify it in principle, in practice one cannot verify it directly.

the center is completely black i.e. empty.
The question is if that is true. I doubt that.

Apply your own standards. You don't even have a calculation. At least
provide something better than "I doubt that" to support your claim.

One question is: if there is empty space around a BH.
At page 29 G'tH writes:
" Thus, as soon as matter falls in, the marginally trapped surface
is replaced by a larger one. We can therefore conclude that
the area of the horizon increases when matter falls in."
Which implies that the region is not empty.

Not necessarily. At least classically, it reaches the singularity in a
finite time, so the volume just beyond the horizon is empty except just
after something has fallen in.