What a great topic! Thanks for posting.
Well here,(USA), we did try call block type phones. It worked for a while until the robocallers created software the spoofed the numbers to a new number on every call. I actually spent $120.00 for my fancy call blocking phone system, which became useless.
Now the PC scammers, usually Asian, mostly Pakistanis, don't robocall like the others do, but they are nearly as tiresome, unless you want to have fun with them. I once kept one on the line for half hour talking about Windows, but he did not get which windows I was discussing, security, warranty, etc. It was only when I asked what he thought of cleaning them that the penny finally dropped...
But here, VOIP these days, there is a service, free from some providers, that solves the problem with a simple alteration to all inbound calls. After a caller connects, i.e number pick-sup, the server asks 'it' a question, eg " to speak to 'name', press ( variable )..' Needless to say only real people can do that. Those losers, above, don't have the time, or resources to comply. Also, and here is the bonus, there is nothing the creeps can do to get around the technology.