>>542286172
A big disadvantage to using anniversary lives for these idol-centered performance is that is restricts the lives as a vector to perform new songs.
ML kind of side stepped singing MTS & MTS Final from the Corona days after they sang them online. There haven't been in-person performances of certain songs from that series yet apart from the breakout popular ones. And Stardom Road has only one song performed at Hotchpotch of all places. BOT doesn't even have live performances at their release events, who knows when we'll see those.
It's usually the case that you go to the annual lives to see the new songs being performed, but as long as they have to write the setlists around the center idols they're going to really build up on the song backlog unless they establish separate lives to take care of those.