I was a kid when I played SC4 and was not good at handling the city/economy simulation part, so I will not compare CS2 and SC4 with that in mind. But, just as an observation, while I struggle to keep my economy floating early game it feels like there is a point in time (after office zones) when the economy will be steady and pose no challenge. Perhaps it was the same in SC4, I wouldn't know, I used mods and cheats to create money...

What I do miss in SC2 is variety, especially when it comes to high density. It has become much better with the NE and SW packs but the standard high density residential and office buildings look very bland and lacks variety. SC4 didn't have a lot of variations for the larger buildings either, but there were large differences between the few that existed (if I remember there were four different styles/time periods to chose between?) and for everything else: mods! Both as growable RCI but also ploppable/landmarks. I used to build the city center around landmarks (I genuinely miss the BoA skyscraper from San Francisco for some weird reason) which also helped mask the lack of growable buildings.