Verizon wanted to cut him off after 20GB. I do not know the exact details. Verizon Data Plans & Features - Terms & Conditions has this clause, which seems to be open to abuse by VZ.
Customers who do not have dedicated Mobile Broadband devices cannot tether other devices to laptops or personal computers for use as wireless modems unless they subscribe to Mobile Broadband Connect. We further reserve the right to take measures to protect our network and other users from harm, compromised capacity or degradation in performance. These measures may impact your service, and we reserve the right to deny, modify or terminate service, with or without notice, to anyone we believe is using Data Plans or Features in a manner that adversely impacts our network.
SPs should provide such an alternative, if they are really serious about Broadband ubiquity. Typical 2.4/5G Outdoor WiFi APs have a range of 700-1500 feet, depending on terrain. LoS CBRS is another option for SPs. If there is a strand, the SP delivering service to your neighbor can mount APs to provide you service. There are ways to address such constraints, if the SPs really want to serve consumers.