The Do Not Call list only stops legit callers, and there aren't very many of them. If you have FiOS or an equivalent system that allows simultaneous off-prem ringing you should check out NoMoRoBo.
https://www.nomorobo.com/
Their computer maintains a list of known SPAMing numbers and if you get a call from one they disconnect it. You still get
one ring, but that's it. It does take a few calls before a number gets recognized and added to its database, but things are
much nicer here in our home. We just don't jump up to answer a call until we get a second ring. The service is free.