Overall fighting has evolved tremendously because of the full contact sport aspect of mma. It's much more polished and a combination of styles to be effective instead of just specialized skill sets. All the years of full contact competition improved martial arts overall because we can see what works and doesn't work in a full contact setting. Of course there are things that different are different from street application of martial arts and sport application, and that's due to the rules, clothes, gloves, etc. Like kicks/knees to a downed opponent, small joint manipulation, 12-6 elbows, strikes to the back of the head/neck/throat, etc are game changers.
But overall martial arts has evolved and will continue to evolve, we've only scratched the surface and slowly moving away from specialized styles to fully evolved mixed styles. There is still a lot of evolution that needs to happen because there are other styles that haven't been fully explored yet.
Everyone in the past have used the same base styles of muay thai/kickboxing, boxing, wrestling, bjj because of all the success of those styles from the inception of UFC. There are other base styles being used by fighters now that mma is expanding globally. The evolution in mma is when everything is fluid and you can't figure out what the original base style is anymore because it is a truly mixed style. Transitions are fluid and everything flows from striking to grappling, to scrambles, back to striking and everything in-between. There will be less stalling options.