What about just using a call blocker app. I use an app that can block all calls not in my contact list with everyone else going to voice mail. It is great and I never miss a call as anyone who I care about that is not in my contact list will leave a message.

I've had a very good experience with Nomorobo. Was getting ~1 call a day at home, now maybe 1 call every couple months gets through. The phone still rings once, then Nomorobo will intercepts and answers it. The spam calls were super annoying, so not dealing with it actually makes my day better.

So far, I have had excellent luck with nomorobo and having t-mobile flag calls as "scam likely." went from 10+ calls a day to zero on most days.

I get maybe 5 calls a day. Nomorobo catches about 90% of them so they only ring once.

The problem with blocking numbers in bulk is that phone numbers are recycled all the time.

If you block 500 numbers and then you apply for a job and the person who wants to call you back about the job just got a new prepaid phone, you might be blocking their number.

If your potential employer is using a burner phone you might have worse problems than robocalls.