If someone invites me to an impromptu Zoom call today, I can join it quickly and easily, because it's likely I was already on my computer. I see the link on my computer, usually in my calendar or in Slack. It takes me a second to click it. And boom, I'm in. Ezpz.
Compare that to a VR meeting. If someone invites me, I'm likely on my computer. I have to leave my computer, go find my headset because it's bulky and inconvenient to keep on my desk, hope that it's charged which 50% of the time it's not, boot it up which takes 10 seconds, clear a safe space for me to stand in my apartment, put on the headset and draw a safety boundary, open the appropriate app and hope it doesn't need an update, and then try to figure out where the hell the invite link is that was chatted/Slacked/texted/calendar'd to me.
The difference between jumping into something in 5 seconds vs 5 minutes seems trivial, but it's massive. It ends up being the difference between me doing this 5x a week vs 5x a year.
What VR seems to need are more killer apps that are habitual, so I use the headset more often, so it's close by + it's charged + I keep an open space + occasionally I'm already using it when I get an invite to use it in some other way. There are all sorts of things that I regularly do on my computer, that I could potentially do better in VR if an app existed, but none does.