I think the video conference market success is also linked to increased prevalence of camera us - i.e. mobile plans finally support streaming, laptops carry a camera as standard, etc. (Covid also increased demand)
If you're going to speculate on what's next for communication, it's probably best to follow the technology.
The market was pretty well primed pre-COVID. We were already doing a fair number of video calls at work, webinars (though usually just with slides) were very much a thing, and I guess a fair number of people would at least sometimes use Facetime to see the grandkids or whatever. As you say, webcams were getting pretty ubiquitous and mobile networks were improving.
When everyone switched to more remote interactions during the pandemic, it was natural to just really ramp up the technology they were already using and a lot of people were upgrading their video and audio gear to make videos anyway.
Not clear to me what is next. I'm pretty sure most people don't want a more immersive experience most of the time and some percentage of people resent peer pressure to be on video as it is--as noted in various comments.
ADDED: I do agree with one of the points I think Ben is making. There is still a lot of UX work that could go into simplifying screen sharing and other, for lack of a better term, multi-mode interactions.
If you're going to speculate on what's next for communication, it's probably best to follow the technology.