I'm in the UK and have had the same number for a decade or so, I probably get one a year? They are mainly from foreign companies. If said countries also had our regulations, and a sharing agreement in place, it wouldn't be an issue.
Having said that, these people will also give their phone number and email address to anyone who asks whereas I do not. If I have to enter a phone number on a form and it's isn't immediately obvious why I should do that then I'll make-up a number.
- people giving their phone number out to companies that share this data, and
- people answering spam calls. Even if you hang up immediately, they probably have an internal metric that says call that number back more frequently.
I don't do either of those, and last week I had more spam/unknown calls than usual: 4
For online forms that require a phone number, I just insert that company's own number.
The foreign companies are basically criminal operations and countries like the US have taken action against them in the past by working with local law enforcement[1].
[1] https://www.scmp.com/news/asia/south-asia/article/2179175/mo...