The observables in our sky do not match any interior metric for a black hole. In particular generically black hole metrics concentrate a central mass, and (from a Raychaudhuri equation perspective) the known sources of shears and pressures that work against this concentration are insufficiently strong to block ever greater collapse. Additionally, shears and pressures enter into the stress-energy tensor. That's why the centre of a BH can be a singularity.

Observations of distant galaxies and the cosmic microwave background do match the (expanding vacuum) Lemaître-Robertson-Walker metric with the distribution of matter-density described by the Friedmann equations. Distant galaxies fill the sky and are receding from us, from our perspective; they are not concentrating in any sort of middle.

There is insufficient evidence to conclude that a big crunch is in our future.

"Pure energy" is represented in the stress-energy tensor just fine. General relativity's Einstein Field Equations exactly relates the stress-energy tensor to the curvature of spacetime. It gravitates, your argument just falls down.

<https://en.wikipedia.org/wiki/Stress%E2%80%93energy_tensor#/...>