I personally get annoyed when people video mute by default, and when I was a manager it was something I would bring up in 1:1s. Lurking on meetings is fine, but if you have a real role in the meeting and you aren't multitasking a meal or something, I feel strongly you should have your video on and be engaged, and most of the time when people are video muting it's because they are hiding their distraction and lack of attention, or else it's reached a critical mass where people are muting just to fit in.
Now that I'm an IC again generally the best I can do to encourage people to unmute is just name them: "hey Joe, are you there?" even though I know full well they are connected. It's admittedly a bit passive aggressive, but it's also a way of gently telling the person they aren't being present, and it's unlikely I'm the only person who notices.
I also mute myself for the wrong reasons, so I'm not trying to make this an indictment of individuals. But it's so easy for people to drift away from their work, especially when you are remote, and we need to look out for each other and not just accept dysfunctional behavior.