I am a German CS-Student and currently renting in a shared flat with 4 other students. We call it WG (living-community) and its really popular not only with students, but i know a lot of young professionals and even middle aged ones that share an apartment (it gained popularity in the 60s, so i think its more of an culture thing that older do not share a flat). If you are in a partnership, you can move out and share…
Also, 1 almost never paid rent. Thanks to him knowing the laws better than me, there was effectively nothing I could do. We couldn't afford this at the time so we forced him out of his room and at least got another person in there for a while. Money is a huge concern for me thanks to student debt. So, when your roommate is screwing around and on the verge of getting fired it stresses me out. Right now I have another roommate who was fired and doesn't seem to care much about finding another job. They're paying rent but the landlord is pretty upset about them being chronically late and only paying $10 here and there.
Every year, "due to market forces" they try to raise my rent by $100 per month, $1,200 a year. So I've been forced to move basically every year because why should I pay more when, magically, getting the exact same (but different) apartment in the same building is cheaper...
Thank god this is my last roommate. I'm buying a house and I can finally sit in one spot for more than 365 days.