it is not directly illegal, but unless you own an actual house (not appartment!) you need a lot of permits (landlord, neighbours, sometimes state). Now europeans will tell you requiring permits is not the same as illegal, but practically it has thr same result.
Thought about the same just yesterday. After a month here in China I noticed I stopped caring so much; stopped thinking about if I go this route I risk getting robbed/assulted; will my stuff get stolen if I go away for a minute, etc.
The worst version of this I've yet seen is too many people in China literally never put down their phone. They are watching tiktok while stand peing, while washing hands, family dinner, on a date etc. It's so sad man.
