Tell me, if not ether - what defines the permeability and permittivity of light? And as such the equations that guide the vast bulk of so-called 'round earth physics'?
But you claim this as a surprise, the specstrocity of space, commonly referred to as vacuum, has been known about since the 1920's.
Modern aether theories make up a large proportion of physics research. GR neither proves or disproved the presence of aether, only that it has to be relativistic and symmetrical, Einstein himself referred to ether, but it never caught on.
As you point out the physics community still get a bit touchy about the term, because a number of people shout aha luminous aether exits, but that theory and old school ether theory was abandoned over 120 years ago.
Today its aired mainly by people trying to take advantage of well known, debated and settled talking points in physics.
Cant speak for everyone, but I have no problem with you calling vacuum ether