I have never been a fan of TS4 and for that reason I had just the base game until recently. I loved TS2 and TS3. I find TS4 graphically beautiful but gameplay is a snooze-fest. TS1and TS2 I believe were so successful because of the novelty aspect. TS1 didn't try to replicate real life. It made me laugh.
TS4 made everything vanilla, boring pre-planned communities, nothing unique. Lost the ability to add color and patterns as in TS3. TS4, The Sims characters don't interact in any meaningful way and the only spontaneous behavior I've witnessed is them escaping to play games on the computer any chance they get...boring. TS2 I enjoyed the sillyness of the game, the Sims dysfunctional behavior, their spontaneous interactions that led to consequences sometimes dark, sometimes weird.
Lastly, to combat the boredom I bought University on sale. I still haven't been able to play the expansion pack d/t off-campus students waiting period to start classes is 5 days and to move a student into the dorms to explore they must apply to the University wait 2 days and hope they aren't rejected. Not having much fun yet. I had hoped to explore the expansion pack that I had just paid for. Not much University gaming going on. The artifical waiting period of inactivity reminds me of Sims Freeplay, and certainly hasn't helped the boredom or experience with TS4.