[qayxc]

> I don't know how you could claim general or special relativity are simpler than Newtonian physics

Careful there! You cannot compare both theories in isolation from observation. Newtonian theory fails to match observation if high velocities or big masses are involved.

In order to "fix" that using just Newtonian physics, we're back to figurative epicycles.

Taking observations into account, SR is simpler than Newtonian physics in that it has a greater predictive power.

Remember that if you come up with something simpler than SR it also has to match observation at least as well as SR.