As someone who has a BA in physics and some graduate work in physics a few clarifications.
Einstein was a genius and was the father of SR and GR and played an integral role on quantum mechanics. In fact his Noble prize was for his work in QM, not relativity. Having said that, GR has moved so far beyond its beginnings he would barely recognize it. He also loathed QM, but that theory also has grown and as much as he hated it, it is one of the most successful scientific theories.
It is almost a century from 1920. If Albert were to be here now, read up on all physics since 1920, he would certainly not be a proponent of ether, or aether, or whatever. Even in the 30's he and others has dropped the idea. The evidence had become overwhelming.
The ether was proposed as the medium through which light was theorized to propagate, as light was thought to be a wave and waves need a medium to oscillate in and move through. There were no other reasons for the ether to exist. Einstein in fact (remember that Nobel?) proved via the Compton Effect and Photoelectric Effect that light has to be made of particles, what are now called photons. Although in the aggregate they demonstrate wave properties, light is made of these photons and particles do not need a medium for travel. Experiments to find it had failed, and then the entire edifice was no longer required so it fell away, as it rightly should have.