Kind of the same. Loved Cities: Skylines to death but the traffic AI killed it for me. It gets to the point where you're stuck building unrealistic designs to workaround the flawed AI pathfinding. It's true you can mod it but it requires a ton of extra manual work to reassign lane routing in each and every city intersection, on top of killing performance.
I'm just waiting for the sequel to the game where they may open up the traffic AI to modders more, or fix some of the stuff broken with the existing engine. That said, it's become kind of the gold standard for city sims so OP should definitely check it out.
The current iteration of the goto traffic manager mod is the presidential edition, https://steamcommunity.com/sharedfiles/filedetails/?id=58342.... It has some features like the dynamic lane selection and an alternative AI model (I think) that help even without manual work. But yes, assigning lanes at intersections, planning the number of lanes accordingly to have onboard lanes and in general avoiding that traffic collides takes some manual work. It can be fun though. I did not notice the performance going down too much.
I play City Skylines only to tune my roads with that mod. It's awesome, but in general I think the game has some annoying flaws, like that bringing dead people to graveyard is like a logistical problem, the blocky zoning makes neighborhoods boring, buildings are never that big, etc.
In CS the only way I found to have even moderately decent traffic flow was to make absolutely every street a one-way street. I don't claim to understand why that helps, but it seems to.
The downside is you have to be very careful where you place your emergency services as you can easily get zones which are too far for firefighters to reach.
I'm just waiting for the sequel to the game where they may open up the traffic AI to modders more, or fix some of the stuff broken with the existing engine. That said, it's become kind of the gold standard for city sims so OP should definitely check it out.