Cities Skylines seems like the successor to SimCity, but even that has some deep-rooted flaws in traffic management and agent flow. Some mods exist to help coax it a bit, but it's still just a broken approach at scale.
Traffic and routing is hard, I get that, but there has to be a better way. Building a city around the routing flaws is not that much fun.
That and 32gb of RAM
Word of warning: if you're one of those people that likes to install a lot of mods keeping everything up to date and non-conflicting can be an pain the rear. There is, of course, a mod to keep track of which mods are out of date or could cause issues, but that's really a band-aid on top of a larger problem. The game is old enough now that many popular mod authors have long been abandoned their projects or otherwise moved on so you end up with things like "MyPopular Mod" and "MyPopular Mod UPTODATE" or "MyPopular Mod FORKED" or "Use this instead of MyPopular Mod".
If I take a few weeks / months between plays this usually ends up with me having to take 30 minutes to an hour to get the mods up to date and tested. Not a huge amount of time, but when your gaming time is limited it's something to take into account.
(Don't use Steam.)
He also has some fun youtube series' where he builds up a region by following a "story" he makes up (or sometimes uses viewer polls). So rather than building a super optimized city, it gets a very natural layout as he pretends to play out rivalries between developers, mayoral or policy changes, etc.
Power, water, etc. randomly chose a direction at a junction, so even basic grid would make it impossible to power a building on the other side of the city, even if the power demand was there https://www.youtube.com/watch?v=tvq6zAMJfOU.
Traffic and pedestrians were attracted to available houses/work, but randomly every day, rather than having a defined home/work location. I built a pedestrian heavy city and would watch crowds of pedestrians head for the nearest available house on a street, before the whole street filled, and they turned around for the next nearest. Same for work, shopping, despite there being plenty available.