Why is a mostly theoretical form of energy and matter more plausible than a hypothesis based on normal baryonic matter?

If "dark matter" was because of micro black holes, there would need to be a lot of them. And they would cause enough gravitational lensing of stuff 'behind' them that we could see that they are there. And so far ... no luck finding them. One result:

Dark matter is not made up of tiny black holes

Then it is back to the multidimensional drawing board.

i’ve seen a couple vids on the topic.

Where’s Einstein when we need him.

It is fascinating to read this stuff but it is way beyond my understanding of the astrophysics.

It is not Dark Matter, it is Dark Light.

It sounds more like a hypothesis than a theory. Plenty of work ahead to get it to the theory stage, and I'm sure it will be interesting to watch the process.

They're neat, bundled, and resolve a piece of the data. Sometimes the underlying hypothesis is tweaked to make it work--which is fine for a hypothesis, that's what we do as we get more data to disconfirm one prediction but want to improve on the hypothesis.

But if it works there, it has the same problem that the "tweaks" produce: instead of a single hypothesis there's a range of hypotheses in the same bin but which make different predictions in specific contexts. No one handles all the data without some pretty unprincipled changes to the equations underpinning the thing.

Then again MOND and its numerous flavors is really too incomplete to call a good "theory", so it's hard to completely rule it out. Work continues.

Note there are a number of papers out there that look at examples where MOND requires really extensive work and loopholes to make it work. One-sided gravitational distributions of matter or even gravitational lensing that MOND can't account for so far using analysis with regular matter, even black holes, without some truly exceptional and one-off exceptions. The kind of thing that a good theory should rule out. Like I said, work continues.

I may have to teach dark matter in my high school class, but I also point out that it's less a theory than a hypothesis, "We can't explain this so let's make up some crap to make it work". Again, a nice hypothesis, and work continues.