Maybe a silly question, but without video isn't this obviously fake? Or is it normal for all participants on a call to be audio only?

Depends on the company. At my last job it was rare for anyone to have video on in remote meetings, and at my current job it's rare for anyone to have video off.

Yup.

At the company I was at from 2014-2021, cameras were always off.

2021-2023, there the cameras were always on. Even during the all-company meetings, at least 80% had their cameras on. Though it was a small company of 75 when I started and 180 when I left (though it was becoming 135 as I was leaving).

At my current place, it's kind of a mix. Small team of 3-5 people, usually on. Larger group meeting, most people off. All-company (about 300 people), only about 50 cameras.

It's normal in many places for the only video to be shared screen

Pretty normal. Camera's usually stay off unless it's a 1-1, presentation, or maybe a VP level call.

If you find use for this tool, chances are good that you're in an place where all the participants would be audio only

You get it.

Depends on the company, the team, the agenda etc

Totally normal. The only time I ever used my camera is conducting interviews.