The calls that come in as a local company/office/service to make them seem like someone you'd want to talk with are SO irritating! I just don't answer, unless it's a person I know.
As far as phone numbers being sold and used - that's not the only way you get calls. Even 40 years ago, computers were auto generating numbers and dialing them. No way to stop those from coming through, either, although at least they don't know your name and other information.