I suspect dark matter is really a miscalculation; the missing matter is in super massive black hoes.
LOL
Perhaps one needs to “Think Differently”
What is Null Physics?
Null Physics is the analysis and quantification of the relationship between the physical states of existence and nonexistence. This relationship leads directly to the intricate four-dimensional geometry of which matter and energy are composed. This geometry is used to explain and quantify many of the properties of matter and light, ultimately leading to a unified cosmology that demonstrates, through logic and a wealth of empirical evidence, that our universe is an eternal equilibrium system.
No need for anything that exotic. We could also guess that deep space is less empty than we suppose, filled with myriad asteroids, planetoids, and failed stars which can’t be seen directly.