I have relevant personal experience here:

At a previous job, I didn't have a company phone when I got set up, so when I signed up for a tool we all used, I used my real phone number. Unfortunately it was an American company, and from that day FOR YEARS I got spam calls, which I never got before.

I can't prove it was them, but it feels like I got too naive because there was never trouble giving my real number to services...