Players are leaving the game at record pace. The remaining players need servers with other players to have something to do.
People want to move to the servers that aren't gasping out dying breaths.

Having anything even remotely viable to play on as 'congested' at a time when players are already losing interest is a bad look and just leads to more lost subs.
Honestly, the team calling the shots at XIV is displaying incompetence every single time they can