I have my own grievances with the game but there's also things I think it does exceptionally well.
Art style- Unlike in previous tittles I have downloaded hardly any CC for I find the vanilla look of the sims so pleasing.
CaS options/flexibility - I like how you can wear any outfit for any category for any gender. It also lets you pick their walk style, decide whether the sim can get pregnant and so on. About time all these options were opened up. I also absolutely love how you can have unique body shapes instead of it lamely being restricted to "thin or fat". People irl come in all kinds of shapes which (regardless of how much media likes to misrepresent it) don't fit into some predetermined molds.
Trait/leveling system for Vampires and Celebs - I absolutely love how you pick strengths and weaknesses for vampires. It introduces new ways to play, adds some much needed challenge and encourages roleplay. I specifically pick weaknesses which I think fit the character in question instead of meta gaming it by picking the "best" options. I feel like it adds a nice dose of individuality. Celebs are also way more engaging than ever before and the quirk system interesting. I like it how it's a little chaotic for while you can influence it you don't have direct control over it.
Mod friendliness - As someone who uses a lot of mods for Skyrim, it basically feels like I can breath easy with TS4. In this game you can pretty much install/uninstall mods whenever you feel like it whereas in a game like Skyrim you can not delete script mods mid-save. It will leave records and can mess your save so in order to keep playing the same character you need to revert to a save you made before installing that mod. I always do keep multiple saves in TS4 as well, out of habit and because it's just wise with any game, but still... modding is so stress free in this game. Yes, constant updates can be a bit annoying but the main thing for me is that just because some script mod becomes outdated it doesn't mean I'm then stuck with it and can kiss my save goodbye.
Control over households - I love the fact that you can flag households as played/unplayed and then seperately control their auto aging. This was something TS3's story progression desperately needed but had to be solved with mods. I also really like how you can manage households easily and even delete the ones the game generates or move them in as a playable family if you wish.