The Sims 4 has no personality

I agree. I have played Sims almost since launch. I started playing in 2001. The game has been with me for 25 years, and I constantly keep buying EPs and other packs for Sims 4, but I never really enjoy it as I used to, and the reason is exactly what you say: the Sims have no personality. You can make a bookworm sim, and they will go to the computer for fun instead of reading a book. You make a vegetarian sim, and they will autonomously pick a meat dish. You can make a sim who hates pranks and jokes, and they will autonomously tell jokes and do pranks. The only hint in the direction of their "personality" is a negative moodlet because, of course, the sim will hate having made a prank even if they autonomously did it... The whole traits/likes/dislikes stuff seems neat, but it really has no real effect on how the sim behaves. 

I know I'm the idiot here for still buying Sims4 EPs and other packs, but I just keep hoping things will get better. There have been very few packs that have actually brought something in terms of gameplay, for example snowy escape, cottage living and Business and Hobbies, and these are fun for as long as it takes you to explore the new mechanics/places. Once that is done, you are back to your useless sim. 

Having a family is a nightmare, because every sim has to be micro-managed or they will just be stuck in front of a computer/tv until they almost pee their pants, because even an active sim will not autonomously go for a run or exercise, they'll just sit in front of the tv and be mad about it...