Cities Skylines 2 issues has nothing to do with Unity. The game has been rushed out the door and is unoptimized. Like for example the game was rendering full set of teeth on the NPCs even when the camera was far away. Unity can be really fast nowadays if you use it properly. Like with the Jobs system and Burst you can write very fast parallelized code that gets converted to native C++ code.
Cities Skylines 2 issues has nothing to do with Unity. The game has been rushed out the door and is unoptimized. Like for example the game was rendering full set of teeth on the NPCs even when the camera was far away. Unity can be really fast nowadays if you use it properly. Like with the Jobs system and Burst you can write very fast parallelized code that gets converted to native C++ code.