You know the obvious advantage of the new system is, you don't need to focus on only one thing anymore. Before it was like either you were going to build a top tier association team or a team which can compete in league, cup and CL.
There were very few teams being good at both, if any it were some of the manipulators. But nevertheless it always felt like you needed to make sacrifices to be better at one of the both, association or other competitions.
Now both could go hand in hand very well.

I'll be honest, for me personally, as a player who primarily focuses on league, cup, CL, the association mode was very stale. I was happy to keep my place in platinum for the 100T every season and that's it. The top 100 were totally out of reach and full of players only playing association game mode.