To say that spam calls are annoying would not only be redundant, but it'd also be a big understatement. These nuisances are primarily why I hardly answer my phone anymore and they've only gotten worse in recent months and years. T-Mobile is taking a stand against it by implementing what it calls Caller Verified technology, starting with the Samsung Galaxy Note9.
Once Note9 owners get the update, any calls on the T-Mobile network that they receive will show a "Caller verified" message on the incoming call screen, assuming that Tmo itself has authenticated the call as legitimate and not hijacked. It all works based on the FCC standards of STIR (Secure Telephony Identity Revisited) and SHAKEN (Secure Handling of Asserted information using toKENs) — T-Mobile proudly states that it is the first carrier to implement these.
Once Verizon, AT&T, and Sprint adopt STIR/SHAKEN, Caller Verified will work across networks. While I'm hopeful about the prospect of this, I'll have to see its real-life efficacy for myself. Note9 owners should be getting the update that enables this soon, with other phones to get it later this year.