Flesh this out, please?
Why do you call relativity an "illusion" ?
E.g. prediction of precession of perihelion of Mercury was predicted by relativity, not otherwise explainable classically...
Cheers!
The treatment began with analyzing why time and space look the way they did after the A. Graham Bell Michelson-Morley experiment returned a null result. The description of appearances is the point of relativity, which amounts to saying the description of the illusion.