All sensible advice, but it's still an interrupt.
People can contact me in tons of different ways. I prefer in person, voicechat, emails, chat, all above phone calls. Urgency and depth of conversation at orthogonal. So if someone calls me, I really want to pick up because it probably has some urgency to it.
Consider the difference between private/professional availability as well. Some friends don't pick up the first call if they are busy. If people call 2-3 times in a row, they know they have to drop what they're doing right now. I think some phones let you filter calls unless they are coming in a few times in a row. However, that's not really an option for everyone, especially professionally.
I'm not sure if a 'service' to scrub phone numbers is effective. The people that do scamcalls are criminals, and I'm not sure how a negotiation with criminals is going to look like. In my experience it's up there with human traffi*cough* recruiters etc. where if you ask them to delete your file/details because you're not interested (and EU privacy laws), they still don't budge. They don't care. If you sue them for having your number on their list, I suppose that law case is the least of their problems.