or, point out "hey you have something else on screen because white screenlight flashed on your face"
Leaving this company in a month, although they're paying me 2x the local average SE salary here in Sweden.
But if you invite everyone to every meeting, have no agenda, and have awkward silences in the meeting you called while trying to come up with stuff to talk about... then surely people will try to get some work done in parallel.
Even if you have 5 people for 30 min on the call, it's totally understandable that one or two of them find it mildly boring but here and there relevant. For instance they are expert in one of the field touched by your project and they sometimes need to react.
In your ideal state, the choice is for them to leave the meeting altogether and find something else they can focus more on, or to focus 100% on the meeting and spend half of their time religiously listening to stuff they don't really need to hear.
In my experience the result of the second choice is people being more and more reticent to come to meetings, not just because of some hypothetical time lost, but because it's mentally painful.
As an added bonus, instead of having one meeting with 5 people, you need to make 3 with only the parts each members fully care about, and eventually a few more down the line when what they each say in isolation doesn't make sense when assembled together.
A well-prepared meeting is fast-paced and keeps everyone genuinely involved.
For instance, when everyone is in the same room, you’re manifesting you dedicated your time to the meeting. From there, even if participants look at their mail or do something that might not be related, or just look bored, there is some leeway given by the fact they are there in the first place.
In most remote settings, I find this leeway is way thinner, and it is less accepted to be distracted by something else, people will be apologizing in more specific ways to justify they weren’t listenning.