I don't look back at UFC and Brock, you're getting it wrong. For me, it's UFC who turned this sport into a rough pro-wrestling. Yes, as I said, some 10 years ago and back, referring to "late 00s/early 10s". The fighters back then, for me, were way better.
I think Islam, Volk, Yan (even though he was robbed just now) are technically as skilled as anyone we've seen in MMA so far. The LW and BW divisions are shark tanks as well. The talent pool is clearly more diverse than it used to be as well because the UFC expanded internationally through the 2010s and started scouting wider areas. If you put the champs of 2012 against the champs of 2022 i'm not sure which side gets more wins tbh.
There isnt going to be an "after MMA". People are still clinging to the idea that its a fad 15+ years after it started really blowing up. For most of modern boxings history it was completely unopposed, there was no large scale competitor to compare it to or go to as an alternative. Once the UFC got mainstream acceptance, proper exposure and started expanding into international markets (all of which started happening in the late 00s-early 10s) it was pretty much a foregone conclusion that it would overtake boxing within a decade or two.
Boxing has probably been in a decline for more than 50 years. However, the sport seemed to have lost much of its relevance over the last 20 years and there doesn't seem to be much that can turn the sport around. Boxing is not dead yet, but it needs something to jump start it and make the sport popular again
Completely agreed boxing is not as popular as it was in the 80s 90s and early 20s. There was a time when boxing had the golden era. But now there are many more fighting sports that were discovered like MMA and much more and no one updated the boxing terminologies so this lost its spark.