Spacetime is completely made up. They make up concepts to try explain observations, like virtual photons, even though they don't actually exist.

Magnetism is an observable, testable and repeatable phenomenon. It is a much stronger force than gravity claims to be, even though technically gravity isn't claimed to be a force. The earth is negatively charged, and there is an equipotential increase in measurable charge in the atmos. We can manipulate objects to move up or down by affecting their electrostatic charge. No such experiments exist to support the alternative theory. It's all just mathematical equations.

The explanation of gravity from the mainstream is entirely nonsensical from my perspective.