The biggest problem this brings is that top, rich teams, stack up on talent. Look at Manchester City. They have players that barely feature that would have been stars on other teams.
Top squads in this era (2012 and on) are significantly stronger than before. And their competition is non-existent. First off, you lose all the decent squads from Europe as Platini's law of 2009 means that crap teams will make the CL. They make it once or twice in the groups and boom, it's game over for the next decade for anyone else.
Apart from dodgy environments like Greece, (Italy), Albania and Cyprus where the target is probably to steal the trophy so that you get the CL money, in other countries it becomes inevitable as well. Croatia, Switzerland, Austria and others have no domestic competition anymore. FFP and CL money killed it. Add the fact that you can essentially have 17-20 foreigners, you can just have two squads that are stronger than your next competition's strongest lineup in these leagues.
It really needs to change back for the sake of the sport. It is not enjoyable seeing the same teams over and over again.
On FM it is even worse as the money never stops flowing for some of these leagues or teams so they only become stronger as time progresses. You see teams spending 40m on a player that they didn't even need and do not use. Then they sell him for 12m the next summer. FM also doesn't have an understanding of FFP, which means that these silly transfers take place all the time and since their transfer system is not very dynamic, these players will typically then move to a club from the same league as they get scouting boosts for that.
This is also why I cannot take seriously so called records in football these days. The difference level is stratospheric. We used to play vs Bologna or Lecce or Cagliari and we were competing in Europe as well. The difference between us and them wasn't enormous. You were not expected to win all the time. Now you look at the lineups and say "there is no way we should drop points here". You still may, but it'll be a huge surprise.