I suspect people on extremely limited plans know to screen their calls or manage in some way. If not that is unfortunate but hardly justification to upend cell

I suspect people on extremely limited plans know to screen their calls or manage in some way. If not that is unfortunate but hardly justification to upend cellular calling because a few people paid $0.10 / minute extra answering calls from spammers. There are advantages and disadvantages to those types of plans, and that is one of the disadvantages.