Just a small note: MMX didn’t disprove the existence of the ether as the medium that supports light transmission since it left open the possibility that the ether in the vacinity of the earth moved with the earth - the so called ‘ether drag’ hypothesis. The subseguent measurement of the parallax of nearby stars disproved the ether drag possibility and thus the existence of ether.
Draw a circle. Where does it begin (and end)? Or, closer to our current understanding of the universe, draw a hyperbola - where does it begin and end? What exists before its beginning? Yes, there is paper before its apex, but what if the hyperbola is the only thing that exists? Kind of hard to wrap our heads around thinking of that as a description of the universe through time, but no more so than trying to think of some long stringy molecules defining who and what we are.