First off, watch this: PBS Spacetime
The most interesting take - the entire energy budget of a black hole can exist on its surface. The surface area expands linearly with energy.
Huh. So that means that black holes could be hollow. Absolutely nothing would exist inside the hollow shell. Which actually makes sense, if the bottom limit to the spacetime energy field is zero, not some negative number presumably smaller than infinity. And our universe ends at the edge of the real number line, and does not enter the complex plane.
It also explains how black holes can have an electric charge that affects anything outside themselves. (Work with me here. If black holes derive from point-like singularities inside the event horizon, and electric fields propagate at the speed of light, then the electric field cannot flow from the singularity to out beyond the event horizon. Both of these things cannot be simultaneously true.)
Of course, the inside of a black hole would still be the place on the map labeled, "Here be dragons." There could be an absolute nothingness inside, devoid of all energy. Or, perhaps, the place where the complex plane impinges and intersects with our "real" universe. Remember, the gravity at every point inside a hollow sphere is equal to the gravity at the shell of the sphere.