I am not one to spoonfeed especially since the relevant information is readily made available but okay, because it seems apparent to me that you don’t understand the implication of the paragraphed involved and could not think beyond the context.
In average, across all ranks the queue time is 3-6mins, so that means that’s the average queue time in Platinum as it is the average rank of every player of the player base. For very obvious reasons, the higher your rank is the higher the queue times are primarily because the player count thins out the higher the rank.
This is noticeable but not by a large margin for Diamond because the last time I saw, player count is at 10% on it and only goes down even more.
This has many factors such as: the player’s location, whether it was during peak hours, the player’s rank and if the matchmaker is able to find people who satisfy this factors within the reasonable timeframe, probably lots of other factors as well.
Mind you, this was already common knowledge way back when we were still in the old forums, there were a bunch of orange posts there on how the matchmaker works too.
The fact that you were so ready to incite misinformation and blatantly refusing to read the material is so borderline trolling.
People will scream and complain even louder because that’s the easiest thing to do.