I found a novel solution by accident to this. I moved to a new area but kept my old number. 99% of my spam calls are from my phone’s area code. If you are not a contact and a number comes up from that area code, it is spam. If it is my new area code, it is a person or business trying to reach me.
Same (though "I moved to a new area" happened in 2004). At this point I've just blocked the entire old area code and neighboring ones, aside from existing contacts.
As do I. This is a difficult problem to solve especially as the signal to noise becomes worse as abuse becomes more common.
Ive had to wildcard block my area code (since I don't live there anymore) which captures 95% of my daily spam calls - but people can still leave a message to break through my wall if it's truly urgent. I don't see how this could work with SMS.
Even message requests on facebook/messenger have problems where you are unlikely to even see the request unless you check regularly.
No, I have never bought an extended warranty. However, I did today make good money on a business transaction because a stranger was able to reach me. I also had to delete some voicemails about extended warranties. This is a worthwhile tradeoff for me.
You could likely get a far off area coded number.