Unpopular opinion here but I'm pretty sure a big problem with the queues are premades. Premades jump ahead of the line and that can make it so that you're waiting for a match far longer than the estimated time will show. If there happens to be a premade queueing back to back you can end up waiting several hours and never really get a match to pop. So because it is so unreliable it makes it so that anyone that has to plan their activities around a limited amount time has to avoid frontlines/pvp which just further shrinks the already small number of available players.