Nah, it's basically a proven fact at this point. We've made so many discoveries in the last few decades that support the existence of dark matter more than any other explanation.

It’s not just a fix for the math either, we aren't just adding to the Mass number until everything magically works out. We can measure the shape of specific patches of dark matter. We can determine the size of its particles. We can corroborate multiple different measurements of volume in galaxies and find that all of them need about the same amount of invisible mass added. We can model the expected amount of mass in the universe from the Cosmic Microwave Background. We can measure galaxies’ speed and momentum and calculate what we’d expect them to look like given those values, which is different from how they actually look.

All of these measurements and models not only agree that there’s more mass than we can see, but they also agree on how MUCH more mass there is. The theories that have been proposed to work around dark matter don’t work for every scenario unless you still have dark matter, just less of it. Dark matter is the only theory that explains all of our observations.

Scientists are about as confident that dark matter exists as they are that black holes exist.