The honor and ranking meta changes drastically. When queues are seperated, the only people able to compete in the premade queue are the top end premades, which is basically the same as now… Except.
When the queues are seperated, solo players are able to gain more honor. That means that solo players outfarm the bottom end of premaders, forcing them into solo queue.
When most of the people are in solo queue, not only can they not play with friends any more; but they also have to compete with bots for honor. Because bots are now competitive honor farmers, topend premaders can no longer say “right, we’re capping honor at 850k so we don’t all have to grind 7 days a week”. Bots don’t care what players do, they just farm and farm, so the honor cap becomes higher than what a 24/7 leecher bot can farm in solo queue. (and if you remember from the AV meta, that’s quite a lot)
Furthermore, solo queuers then complain about the amount of bots in their game and how unfair the matchmaking is, once they see that 6/10 of their players are warriors and 3 of the others are “I dont play support” Ret.
So basically, seperate queue means top-end premades have to play more. Bottom-end premades (friends and casual guildies) can no longer play together, botters can honor farm again, people can effectively afk-leech again and the puggers are still miserable.
Or, things can be left as they are now, with just the puggers being miserable.