@419mainstreet Keep in mind that blocking numbers also just sends them to voicemail by default, which might require one to still have to delete useless messages from there, unless the blocked/declined/busy conditional call forward is redirected elsewhere.
Also unreputable international spammers could care less about the DNCL, and would probably use it as a priority-call list.
As promised, I have contacted the CRTC (via their chat help system - very prompt response). The CRTC regulation requiring providers to provide a call filter for spam and robocalls is not in effect yet. It will be a requirement as of June 2021. It applies to all providers, whether the plans are prepaid or not.
So it seems this is coming. Just don't take any of those threatening CRA robocalls to heart in the meantime.