You read my mind. City builder games are unrealistic in a bad way that defies intuition and prevents you from modeling a real city. This has been my huge frustration with Cities Skylines, which looks great but where ambulances take three months to reach patients.
With those timescales in mind, people must go decades between annual checkups.
I think the problem is that a realistic city builder is going to require too much processing power and would probably be unfun.
If you want traffic that moves in real time, then your day/night cycle needs to also be real time: 24 hours. That means that if you're only playing in 2 hour gaming sessions, it's going to take nearly 2 weeks to simulate a single day. For those that truly want realism, that's great. For most gamers though, that's gonna be a non-starter.
So of course there's a problem: You can either have traffic moving in real time, or you can have a reasonable day/night cycle length. You can't have both.
The compromise that city builders make ends up with what you said: Ambulances take 3 months to reach patients, even if they're only traveling a mile.
That said, I do think that Cities: Skylines could do it better. The amount of semi-truck traffic in that game is absolutely insane. Easily 4x what it needs to be. You make an industrial district that's only ~1/2 of a square mile and it's an absolute zoo of semi-trucks, requiring some crazy traffic engineering to make it not be a gridlock.