Well, since you've taken the trouble to bring this up now more than once, I'm curious to dig a little deeper. The following questions are strictly rhetorical - you don't have to give an answer to anyone but yourself.
First, if you're getting matched against diamonds and predators then there's probably a reason for that. I'm not saying it's a good reason, or a fair reason, but at the very least the game thinks that while you may not be diamond yourself, that you may in fact be diamond adjacent. And that means that when the matchmaker scrounges to fill a diamond match... it's going to go to you and people like you. Platinum maybe?
Second, if the game demonstrates a consistent inability or unwillingness to match you against players of similar skill, then maybe it's time to play less ranked and more pubs? Where the distribution curve will show you (more or less) exactly what kind of match you're getting into AND give you the opportunity to quit at any time, including while still in the lobby, with no penalty whatsoever. Just re-queue.
And not to beg the answer, but how many hours do you typically put into a game before you feel like you really REALLY understand how it works? Do you feel that 2000 is that number?
Obviously you're playing on PC. It can't come as news to you that your platform of choice is a cheaters' playground. And the depressing part is that this applies to any game you care to name, so it's not as if you could escape the cheaters just by quitting Apex and moving on. There's no safe place to move on to. Or so the internet would have us believe. I haven't seen much of anything to convince me they're wrong. Or even exaggerating.
And to come back full circle, when I hear someone describing high level gameplay as a brick wall then I'm not doubting the truth of that. I've flirted with high level play just enough to know that the brick wall metaphor is accurate. I'm not questioning the difficulty of those lobbies, but I'm coming back to how it is that you end up in them. The matchmaker using you as feeder fish for better players is definitely a thing this game does, but also... and again, no answer required beyond the one you give yourself... I'm wondering if there is anything else in your stats that would push you into these lobbies. It doesn't seem as if it would be kills or wins, but I still wonder what your k/d and win rate look like. Average damage comes to mind. And also, a few other perennial EA favorites: willingness to re-queue after a loss, average session length, use of comms, stacking... I don't know if any Respawn employee would confirm or deny these data points as relevant, but I've put a few hours into this game myself and I feel fairly confident that these factors all play a role.
Just some stuff to chew on.
