Does The Sims 4 require a trait overhaul?

Yes - the majority of the traits affect emotions, and emotions don't meaningfully impact gameplay or impart severe consequences on the player, rendering most traits useless. What they really need to do is create: a) a want/fear system, b) a mood/inspiration system with consequences of failing to fulfill the sim's wishes/needs and then finally c) traits that impact sim actions, wants, fears and desires. They also need to focus on relationship consequences for cheating/fighting etc. I think the Sims 2 did all this really well and if they mainly copy/pasted that system here it would be a huge improvement.