In their recent AMA, the devs of Cities Skylines 2 revealed that their target FPS goal is actually 30 FPS. This is amongst recent outcry of poor performance for CS2.
Some quotes:
"...we just don't believe there would be a long term benefit in setting the target to 60fps,"
"It is worth mentioning for a game like this, the performance target is to run at steady 30FPS minimum (not 60 or more)."