You can't get a proper picture only from Ranked mode, since Arenas ranked system wasn't really good thing to play, especialy in the late seasons against cheaters. Of course BR is much more popular, because it's the core of Apex, the main gamemode. But it gets boring over time, and players need something else to play. That's why we're getting LTMs, That's why Mixtape exist. But none of these is even close in terms of popularity, Three Strikes being an only expection. Try to search Arenas on this forum, or Apex reddit, you're gonna see a load of posts about how people miss it, and even how many players quit the game because it's gone. The main problem with Arenas was the poor development, which is the problem of the entire game these days. It's the same thing, absolutely identical pattern, but in the much bigger scale. That shows Respawn can't learn from their mistskes, and the same thing that happened to Arenas, is about to happen to the Apex itself.