the underlying problem is that spam of any format is very cheap. if just 1% of people respond, it pays for sending out all of the robocalls/texts/emails. it's very difficult to legislate against economics like that

what we need are better spam filters for calls, texts and physical mail. allow people to pay to blacklist numbers that have a high probability of being spam. I'd imagine that "real" numbers get an average level of incoming calls, messages and push notifications that a spam number wouldn't

it might also make sense to allow private or government white listing. ie, prove that your phone number belongs to a "real" person potentially by paying a one time application fee. with enough adoption, that could change the spam economic equation