A lot of people point out that telecom companies should do something but aren't because it's lucrative for them or too expensive to fix. Are telecom companies not realizing how much they are hurting themselves with this in the long term? People will stop using phone numbers altogether. Using the phone has become such a pain, at least in the US, that whenever I can, I used different ways of communicating. WhatsApp, iM…
That is exactley why centralized solutions are winning the market over decentralized ones. No one wants to deal with evil actors within decentralized system. Users are even ready to give up open protocol for proprietary one (imessage, etc).
Closed platforms can also be spammed. Twitch, HN comments, etc.