You’d be surprised. Maybe YOU don’t get calls from the same number (though I do at times) but it seems like scammers will use one number to call 100,000 people then switch to a second number and call again. So as long as someone reports it lots of people will benefit. It’s not a random number per call, which would make this approach unfeasible.

This shared block list is basically how Nomorobo works and it’s quite effective for me.