Here in France, the ISP "Free" has been doing this for at least 10 years, and they also have a special "hotspot" for mobile phone (called "FreeWifi_secure") on which you can connect using EAP-SIM.

Nobody cares as we have optical fiber in most of the places.

Main problem: when you're in a public transport in the city and your phone tries to associate with the random access point it can hear, leading to a potential disconnection as you're too fast anyway.