Absolutely crucial! We have meetings with 14 to 20 people but often one dominant speaker (like in a presentation). The main speaker gets totally lost among 16 other images and it becomes hard to keep focussed while looking at 15 other people that are also trying to focus on a tiny image.
It's an absolutely basic feature in every other video conferencing tool and I am astonished this was not implemented from the get go. Please please please implement asap. Thank you

I would like to add that perhaps each person seeing the other's video as bigger than their own would be extremely helpful in language teaching for one-on-one classes.

yes like the ability to "pin" a screen or user on Zoom so that it shows up larger or as the main view, especially on a recording.