I think there are many ways we might fix the game. However, none are really as certain as going back to an older settings that had a proven population. The question is, which one?
If we go back as far as I started playing this game (way back when?) it was a time where private teams were the only thing around (aside for occasionally some public teams). That is one time we could go back to. However, it is questionable whether in 2020, we will be able to set up that kind of game again. It also did not have the highest population... it is probably better to go further in the future than this.