There is a spectrum of types of Sims players. I wouldn't really call it Barbie more paper doll (basically CAS creators), playing house (from RL mimicking to baby challenges), skill grinders/collectors, builder/creator, and puzzle/adventure (like Sims 3 WA/Sims 4 JA).
As someone who, as a child, played with both Barbie and Lego, Lego did way out last Barbie. I was a Medieval and Pirate Lego collector/builder, I got as far as one deep sea submarine too.
I'd like more building, puzzle solving, customizing, etc. features over bloating CAS, and RL interaction/game style fluff. It doesn't mean there can't be some added, but more depth and creativity—I think will help the game last longer.
I'd like it if they released a World Editor feature (Base Game), so we can finally edit the neighbourhoods (add insects/butterflies/etc. to all worlds if we want, edit/add spawners/etc. and add/remove lots/shell buildings/etc.), and user made tomb/mission/quest building so we can share on the gallery to add gameplay for others.