I’m just a guy who minored in physics, but my vague understanding was always that dark matter and dark energy have always been considered placeholders of sorts, kind of just names for “we don’t know what’s happening here”. But OTOH we can see what clearly appears to be matter deflecting light reaching us from afar, and that matter doesn’t seem to interact with the electroweak force…so maybe dark matter and dark energy have different theoretical statuses.
But I haven’t looked at physics in ten years so the above might not even make sense.
> dark matter and dark energy have always been considered placeholders of sorts
It's not a placeholder. We can measure how fast galaxies rotate, run some simulations with the current law of physics and calculate how much mass they have. Also etimate how much mass we can see. They are different values!
Dark matter is the hypotesys that thae different is caused by some mass instead of an error in the laws, or the measurements or something. There are a few hypotesis about what the dark matter actualy is, and they are very different and nonegives a good answer.
We can compare the missing mass of calculated with the rotation and other calculations like gravitational lensing and backgroung radiation. IIRC all the these different methods to calculate the ammount of dark matter sorta agree, so people working in the area are quite convincing this is the solution to the problem.
> "we don’t know what’s happening here"
That's more general. It may mean that equations are wrong. Some people proposed corrections to the equations, but all the proposal so far don't solve the problem. (For example, MOND needs use a new constant a0, but to get the correct result in each galaxy we need a different vaule of a0 instead of a single one for all the universe.)
There are many people who claim to be professional academics in the field that believe they are real for personal and political reasons. Many such people will fight to death in a great holy crusade any notion or expression that the dark matter/energy aren’t completely real as the air you breathe.
To me, that alone suggests they aren’t real. I suspect the unstated motives are related to funding and/or need for validation by consensus.
People argue most fervently about things when you can't meaningfully measure the difference between the viewpoints. Because, of course, that argument can go on forever since no one can prove either way.