I only read about video sharing in a group, not every-user-to-every-user calls. Which easily eats up a lot of bandwith (, at least on the server if that is the place that pre-renders all video tiles together for lower network load in sum).
You can turn on your video in a user-to-user call too.
I meant star hierarchy (server, everyone else is a client) versus peer to peer network requirements. Not group call vs one on one call types.