Forgive my ignorance. I'm simply troubled by this mystery. As I understand it, it's not known why the speed of light is constant. I will think deeply about the questions you've posed, do some more reading, and reply.
I think that space moves and light doesn't. Entertain it as a shift in...
Sorry, that was dumb.
And it's speed is measured in relation to an observer fixed to the earth.
I guess I just think it should be measured against the speed of light. That should be the standard. As though everything is moving through light. It would make things simpler.
I am a laymen. I just thing that if the speed of light is constant then all acceleration should be measured against it. It doesn't move. Everything moves through it. Is that how it works? This has been making me anxious.