After more hours into the game (and with a 44k-city population), I've decided to put the game to the side for now and might have a look again in a few weeks or months. On the one hand, there are some bugs, that just break the game, like exports/imports not working properly or garbage incinerators being broken. On the other hand, I really can't stand some of the mechanics they've apparently implemented to make the game "easier" and almost impossible to fail. There's a whole controversy about no real simulation being in the game and while some of the things make sense, I still have doubts whether it's actually as bad as some people think it is. I think the bigger issue is that there are a lot of invisible/semi-visible safety nets working in the background, that keep your city going and growing even though something's terribly wrong with it. For example, there's this mechanic that garbage trucks from neighbouring towns come to your town to collect garbage. As a result of that, I never actually realised that the garbage incinerators were broken and didn't actually work, because I never had any complaints about garbage piling up by my citizens. Outside garbage trucks just came in and collected everything without me getting notified about it or me having to actually pay for it.
I also had an area in my city where there were only pedestrian roads and loads of office buildings. That worked at the beginning, but later I noticed that there were huge traffic jams on the pedestrian roads. After some initial bewilderment I realised that, if a worker can't find a place to park outside the pedestrian area, they just don't give a fuck about the pedestrian roads and use their car to get to their workplace. Everything without notifying me that there's actually an issue. If I hadn't put some high density offices in there with loads of new workplaces, I might never have noticed that there was an issue with parking spaces, because workers would just have kept sneakily using the pedestrian streets with their cars. That's just not how a city building SIMULATION should work. Especially not after the way they've sold their games to the public.