Sure, a lot of people use it, because it exists. How many of those people would actually say it's a requirement to be built into it though? There's plenty of other options for screen sharing they could use. I don't know though. Maybe a lot of people actually do consider it a critical feature. I doubt it though. I've used it a few times with my group, but it's only ever a "do you want to see this?" It's just a bonus, not a requirement.