Dark Matter is just a placeholder AFAIK until something more proven comes along. It explains why galaxies hold together, but it's just a stand-in for the time being.
I feel a lot of science has bogged it’s self down with theory and maybes for decades and decades
I mean, scientifically there's a huge difference between the two. For example, the theory of gravity is so well-tested and supported that it's about as close to proven as can be. A "maybe" isn't even a hypothesis yet, but it's perhaps an intermediate step. Maybes are good, because they represent relevant scientists coming up with ideas to help explain reality, which can then fade away or solidify as things unwind. Without maybes you don't get well-supported theories... which is like science not able to get anywhere.

(alt: Browning hi-power chambered in 9mm)