However, on quantum scales, photons are considered to be excitations of the EM field. Is this field "stationary", like ether in LET, then, in order to be in agreement with SRT? I am probably mixing apples and oranges here, but I wonder what's the point of this field then, compared to ether?
Furthermore, I've seen articles (disclaimer: not really scientific) which try to explain the double slit experiment as if the "ether" (or whatever "medium" or "field" you are considering) is being disturbed by the photon into waves, similar to what a tiny rock would do when thrown into water. Observing a photon at one of the slits would absorb (much of) its energy, making it unable to disturb the medium enough to show the pattern.
Mathematically, it would probably boil down to classical interference explanation, which I believe correctly calculates the behavior, but I am presuming it would be a much more down to earth explanation compared to "shut up and calculate".
So obviously, something is wrong about this reasoning?
To address the comment from @CuriousOne, I believe that many misconceptions exist about QM ("nobody understands quantum mechanics"), but it's still strange to have this information presented in this way in e.g. Wikipedia, which everyone is free to edit and improve.
For example, if you read about the double slit experiment on Wikipedia:
The modern double-slit experiment (...) displays the fundamentally probabilistic nature of quantum mechanical phenomena.
Wheeler's delayed choice experiments demonstrate that extracting "which path" information after a particle passes through the slits can seem to retroactively alter its previous behavior at the slits.
Internet is filled with articles and "interpretations" like this, which seem far away from Occam's razor (I hate comments that photons "don't like to be observed" and "send FTL information to their entangled buddies when someone observes them"), but still the usual answer on Physics SE is "everything you've read online is wrong". You could probably even recommend 10 books on the subject, and each of them would have a different "interpretation".