We use an
https://www.obitalk.com/obinet/ Obi device for our home phone that uses google voice for the service. No only is it free but it does a very good job with spam protection. We still get valid marketing calls from local charities and such but most robo calls are block. We still have to pay $15/year for 911 service but the rest is free, after giving google access to our very limited call history and voicemail comes via email.