In a business context, I try to route substantive communications through email (or, if internal, through systems like Slack). There's nothing like a searchable corpus to minimize ambiguity, commemorate who said what, and when, and in response to which questions.
Likewise, there's a certain kind of project counterparty who inevitably tries to drive substantive communications through phone calls -- specializing in the dreaded dozen-person multi-time-zone conference call, featuring the ever-popular ten-minute parade of welcome tones, "who just joined?", and mystery attendees. These email-avoiders are the ones for whom calls are a tacit means of trying to project power, and ambiguity is a project management feature, not a bug, bound up with their own personal risk management strategy.
You probably know the type: when asked a detailed question by email that requires a specific and accountable response, they reply "Let's set up a call. -- Sent from my iPhone".
N.B. I like iPhones just fine, but please, turn off that sig.
That said, there is typically no intelligence behind 95% of conference calls with more than 5 parties.
You can defuse a potential conflict by voice call because the medium allows airing of issues in a more candid fashion, and allows more rapid convergence onto common ground compared to text based communication.
I think that bad news is best communicated along channels that allow some kind of non-verbal perception (on a phone call largely by judging the nature and length of the silences). Face to face is best, but synchronous voice communication is a second best.
Those situations are so common at Microsoft that they put a button in Outlook specifically to mute those threads.
Be careful with "nothing to hide" arguments. All else aside, sometimes it's nice to voice a frustrated opinion about a person without creating a permanent record.