Bring these hidden lot traits to the game!
From what I learned on sims.fandom.com, with City living there were two additional lot traits only applicable to apartments, the Cheap and Pricey lot traits! They're not used in the game though.
A screencap from the site (edited by me).
Since this game is too easy (unmodded) and sims just drown in money at some point of their career because the living costs (especially an issue with apartments!) aren't growing accordingly and there isn't much to spend on, these traits added as lot challenges would help with the issue greatly! Or even just normal apartment traits, I'd happily take that too.
Please take into consideration bringing these traits back to the game for a more challenging and interesting player experience!
[CM - Edited title for clarity]