If you are talking about guys "killing it" at the black belt level you are talking a very small handful of 6-10 people. People who often switch from team to team, including many you mentioned, or form their own with already established competitors.
I think the majority of your time should be spent drilling the most successful moves at black belt level, but the game would never evolve if people didn't try to bring new stuff into it, and that doesn't happen over night.
Sure it does not happen overnight. But several new evolutions have come and gone in the time since the rubber guard got wide exposure. They did not happen overnight, but they sure happened a lot faster and more definitively.
I mean Mastering the Rubber Guard was what, 2004? Since then we've had 50/50, deep half, the berimbolo, leg drag passing, RDLR, double guard pull, the Marcelotine, etc. All of those have been more successful generally.