All you need to explain away Dark Matter is to take into account Electromagnetism - specifically, the fact that plasma is comprised primarily of charged matter (ions, electrons, protons) which self-assembles into what are effectively naked wires through which flows a current thanks to the good old right-hand rule; Birkeland currents. These can exist at multiple orders of magnitude. Get 2 big enough currents meeting and they can form a spiral galaxy, without any need for any Dark Matter. If you really want to look into it I can highly recommend Anthony L Perratt's "Physics of the Plasma Universe", second edition. You can also see the results of a computer simulation demonstrating this as long ago as the early 1980s here:
https://www.plasma-universe.co....
The trouble is that the majority of astronomers do not understand basic plasma physics, despite the fact that you can demonstrate all of this in the lab at a small scale, and we've had confirming observations from multiple sources in the solar system for over 50 years, which is somewhat embarrassing as it's estimated that over 99% of all the visible (and proven) matter in the Universe is plasma.
