A fun video related to this and Brazilian Jiu Jitsu is this one: https://youtu.be/xeUQlXmzuZ8

Basically my understanding is that high-level competitive Jiu Jitsu (Gi) can be extremely dull to watch, because of the point system disincentiving taking any risks. So that's when No-Gi submission-only competitions became popular to watch. 20+ minute rounds without any points scorable for the first half.