I was introduced to the sims with the sims4 and I played the sims3 for a while after that. There was a while where I played both the sims3 and the sims4 but I had to give up on the sims3. The performance is so bad on my computer and I have a gaming PC which can run a lot of the latest games on ultra settings.
Other things that made me lose interest in the sims3 was that a lot of the sims looks the same, they also have strange behavior which I assume was introduced in updates and other packs. I got love letter in the mailbox every day, got invited to go on dates with complete strangers, literally every sim I met was introduced with a flirty tune, I had a party and every sims was going around, pointing fingers and laughing, I took my sim to university and all my roommates almost starved to death because they could not take care of themselves, if I leave my sim to take care of their own needs, they will watch tv until they starve or their bladder is so low that they complain.
I downloaded a bunch of mods to help remove all that and used NRAAS to fix the performance...somewhat. Now I have encountered a problem where the game is just laggy no matter what I do so I have just given up.
Sims4 is more stable, and gives me more customization, and the sims behavior are not as annoying, they can actually somewhat take care of themselves. But I do miss that there was more to do in the sims3 and I think we can do that without sacrificing performance. Especially in 2020.