After 20 years or more on this game, I just felt I needed to create an account in this forum to state my opinion. I could go on for a couple of pages but would run into the tl;dr so in short (again, it's just my opinion):
The ME is great. It is also broken. So terribly that gets frustrating to watch at times.
There's roughly a 20% of it that could and should be fixed (in FM2021, no rush) and another 80% that can't - It needs to be that way because, simply put, the developers need to come up against millions of people trying to break and exploit their ME. If it wasn't built to behave that way, the outcome would be much, much worse. Nobody would enjoy winning every match by a margin of 5 goals.
I'm 8 years into my save and facing Newcastle in the FA Cup final. Just 2 weeks before I beat them 4-1 for the league at home. I go into the final using the same tactic (4-4-2 attacking) and lose 1-2. Yep, they scored from a perfect counter and an indirect free kick while I had a trillion shots, CCCs, balls hitting the posts, strikers passing to their keeper, same old same old. Ok, no big deal. These things happen (not). But it's fine. I lost a cup (won the League the same year). But then just for laughs, I reload just before kickoff and I use the game ready-made tactic 4-4-2 - Wing Play. I use the same 11 players which don't fit the roles AT ALL and the same Team Talks. I win 4-0 having 8 SOT, 1 CCC and 0 HC. My players are just THAT good compared to those of Newcastle.
This is NOT a valid experiment by any means. I understand one has to run this 100 or 1000 times with different configurations before coming to conclusions. It is just a recent example but what I will state right below is my opinion after, like I said, 20 years (not game years.. real years) in the game and thousands of hours watching and analyzing stuff about it:
The game "studies" the way you play, your tactic, your players, your strengths and weaknesses and tries its best to counter them, using the resources it has available (AI managers and players). This is all well and fine. But when your tactics/instructions/etc and players abilities combination is just too strong and every game tends to end 8-2 in your favor, it employs "stuff" (call them super keepers, stupid acting world-class players of your own that all of a sudden can't shoot or pass to a free teammate 4 meters away to score an easy goal) to counter this. You still get 30 shots and 20 on target and maybe score once or twice, while your AI opponents using their limited resources in an absolutely fair way score the same. That's all it is and it can come out 2-0 or 0-2 or anything in between.
All that said (which might be just my wild imagination and absolutely untrue), FM2020 is a fantastic game and I will continue enjoying it as much as I can. Except from the times it makes me wanting to break the monitor. So maybe every 30 minutes on average :)