True - I have not played basically at all other modes vs ranked where I have like 10k+ hours out of mine total 12, 13, 15 idk at this point tbh.
At the same time I have played I guess all of modes except new 1v1 and there was one with coins and respawning where most got 4k and 20bomb badges recently - skipped that too. Yet your mentioned issues - matchmaking, skill gap, hackers - are present in ranked at all levels as well. So you can't say that this is only Mixtape issue, quite sure system for matchmaking is the same for all modes.
On the other hand how I view gaming online and especially in team games = it is not about "what I want to do" it is finding balance between "what I want to do" and "what others want to do" and how the game is suppose to be played.
Typical example from my first experience online - Need for speed. Players line up, 8 cars, 4 lap race. One dude rages after first corner where he failed, turns around and starts driving in opposite direction creating head collisions with other 7 players => that affects other players and they lose their racing lines, positions.
Player is just sore loser imo. Came for easy win, lost in first 10 seconds, did not bother to try and even more so spoil the experience for others.
Same with Apex. Each mode has its own goal around which game mechanic is built, balancing done etc. So you say in your example that dropping hot and leaving is fine and don't agree with that as pubs = ranked just without RP on the line, a bit less stressful but overall its goal is to mimic ranked game scenario or at least main goal should be winning the game because again we can make an argument that there is no point in getting kills/assists as in pubs you don't get RP for it vs ranked where in higher levels you can't even get positive outcome just by winning the game, you require to have certain amount of kills/assists.
There was this mode with respawns so people would not basically need to leave the game to requeue - cool, there you can do all you want how you want, that is just a meat-grinder type of play, mega damages, mega deaths, non-stop running and gunning basically for the sake of pressing buttons and getting dopamine rushes for all the numbers and kills and what not.
Apex community unfortunately consists of 90%+ very egoistic players = you come into team game to achieve PERSONAL goals. It's like going to play football and just ignore other 10 players on the team. Only difference in football you would be rolled over like a b#%@ nice and fast while in Apex with all assists and cheating and balancing you actually have a fake feeling that you can make it / in lower skilled lobbies you can make it without a team.
Which results in people being super selfish, my way or high way mentality, unable to talk and reach agreements with other people to go for the same goal, bending rules is viewed as normal, anyone better than you = hacker without even looking at their footage (unfortunately limited also by the game)...which all creates environment what we all so well know = pretty much it is impossible to play, mostly negative emotions unless you find some "weird" goal like dropping fragment and dying 100 times in a row at which point your sanity should be questioned and question "is this game really for you" asked.
The fact that we can do whatever we want on internet does not mean automatically that we should -> abandonment penalty is just a strict (10min or whatever) reminder about it for people who think they are better than others and others must do what they deem necessary.
p.s. Valorant also has similar system - queue skipping - and imo it works really well, it makes you learn how to play with good and bad players, how to be along for the ride and how to take the lead, how to endure being rolled over while still winning as a team, be happy that your teammates did so much better and carried you as well as remain humble when you get into "bot lobby" and just roll over others. Much more valuable time spent vs what is happening in Apex where even at so highly praised Masters level in ranked people go Fragment with 6 teams and couldn't care less about anything than their ego.