It could have something to do with data sharing, which people in the US (myself included) seem to do more of compared to e.g. those in europe (in my experience)

It could have something to do with data sharing, which people in the US (myself included) seem to do more of compared to e.g. those in europe (in my experience). I get 10+ robo/spam calls a day (to the point where I just gave up on answering all unknown numbers over a year ago) but when I do answer the occasional one they seem surprisingly targeted. I was searching for health insurance a few months ago and that spawned 4-5 robocalls/day all about health insurance. I run a small business that gets ~5 calls/day about financing and a smattering of other cold robocalls about services people could provide. When I had a death in the family, I started getting robocalls about funeral services and life insurance. I don't know why it's so hard to resolve (why isn't cold calling someone illegal?) but on a personal level it's relatively easy to mostly-resolve by screening calls and limiting your number's exposure (both online and to businesses that resell that information). Lack of regulation, enforcement on what regulations do exist, availability of numbers to buy (aided by metadata on who is on the other side of that number), and a heavier reliance on phones/calls in general (compared to my 1.5 years living in europe) seems to be the biggest driving factors.