It should be relatively easy to identify the bad actors here and I don't mean the spammers, I mean the telcos that make this possible, deliberately so, by essentially "laundering" spam calls.
My response to picking up a number is to answer the call and say nothing. Auto-dial systems will route the call to a person when they get a "live" response. I don't know the criteria but I'm pretty sure it's them detecting noise on the call (which could be voicemail).
A human calling will wonder what is happening and fill the silence by saying something. A machine will not.
I hang up within 6 seconds of this in the hopes that it affects some metric somewhere of this being a low-quality or spam call. I don't know if it does. I think I read somewhere once that it did. I could be wrong.
If a real human is on the other end and does say nothing in this window, they'll generally just call right back. You get the exact same number again then this time I'll answer it.
It is nice to filter contacts vs non-contacts but there are too many things on non-contacts. Businesses you deal with, primarily.
In the email world where obviously spam is a huge problem zombie relays that allow this (which I believe is the primary source?) can get blacklisted. Why don't telcos who do this also get blacklisted? Or at least identified? This isn't AT&T or Verizon. It's the little telcos that connect to them.
But is this all too little too late? I think we've discovered over the last 20 years that we're all pretty much over open networks. It's all opt-in now with the likes of Whatsapp, FB Messenger and so forth.
Oh and while we're at it, can we get rid of this stupid exemption to robocalling restrictions for political campaigning? It's defended as "political free speech". To me, this is nonsensical. Free speech doesn't mean that I should be forced to listen to it.
EDIT: Found an example [1] of the bad actors I'm talking about.
[1]: https://www.theverge.com/2020/1/31/21117477/justice-departme...