This might not be news for a lot of people, but for me this is an episode of "today I found out".
So, I came here to find out why starting yesterday I wouldn't get near instant invites to CC as I was used to. I suspected there was some server issue going on but turns out no. The answer is simply, people are abusing the system.
The ranked CC que is apparently split into two tiers, the lower tier including bronze to gold ranks, and the upper tier including platinum to crystal ranks. Those tiers do not mix. As long as you stay in the lower tier, so never exceed gold rank, your que will be good. Once you enter platinum "this late" into the season, you will rarely if ever see an invite.
Why? Because there is a rush in the beginning of a season where those who are very interested in placing high try to get to crystal rank as fast as possible, and then just sit there and never que again, which they can do because their rank doesn't decay, so there is nothing to gain or maintain. This effectively means that after a while there are never enough players for the que, and seeing as others pick up on that being a thing the situation worsens further, because why would you even que when you know it won't happen?
So it seems my mistake was winning too much and now I can't play anymore. Fair enough I guess.
There are no words for this other than, yeah this is a pretty big blunder. One that honestly could have been prevented during development by thinking for 5 minutes maybe, or doing a Google research for the same amount of time if the former suggestion sounds too wild. But it is what it is, I'm a tiny bit pissed but I won't lose sleep over it. I just won't waste any more time waiting for a que that never happens.