Make silent an option for ring tones and allow call screening.
Allow users to silence the ring and enable screening so users can verify that callers with unknown numbers can be screened to determine if they are spam or calls that are important.
Thomas D. Millett commented
this is a primary reason to use a voip phone system. I use RingCentral but woud rather switch to MS teams business voice but I am not sure I can fully transiton to it without the call screening feature.