Slack implemented something similar called Huddles, but I think is for paid plans only. I personally think Slack calls quality in general are much worse than other services or platforms like Discord or Meets/etc, so I don't know if it'll really help reaching people and companies that are using alternatives for voice.
Huddles uses Amazon's chime backend for audio, so it should perform much better then the current "audio calls" that slack had, though I haven't tried it yet.
