When you stream a Youtube or Netflix video, you can download several seconds ahead over boring old HTTP. It's a one-to-one link, you don't have to upload anything, and you don't need access the user's camera or microphone.
To be competitive in videoconferencing these days, you need:
* Low latency, so people don't talk over each other
* Video and audio compression that doesn't get confused by dropped packets.
* Setup so easy first-time users won't be late to their video job interview.
* Group calls for 10+ people
* HD quality
* Adaptive bitrates, for users on different speed links
* Skip-free audio even if a user's link goes from uncongested to heavily congested.
* Reliable support for every webcam and USB headset on the market, and hot-plugging them during the call, and changing OS permissions during the call.
* Reliable support for unreliable bluetooth headsets and unreliable bluetooth dongles.
* Echo cancellation that works with every device and room configuration going. Including devices that have their own built-in echo cancellation.
* Audio that's clear even in the presence of background noise, and different people at different distances from the microphone.
* Users behind every type of misconfigured firewall you can imagine.
* Roaming between different Wifi access points, and between wifi and cell data while on a call (including links with no connectivity sometimes)
* Never (or almost never) forcing a user to update their software at the moment they're trying to join an important meeting or job interview.
* Update support (or long-term compatibility) for users who don't have administrator rights.
* Graceful recovery if the user sleeps then resumes their device.
* Screen sharing that retains good readability, even if a user has unwisely made the text on their presentation a bit small.
* Screen sharing of Youtube videos without making them blurry or choppy, even if they're embedded in presentations.
* CPU and battery efficiency.
* Free of charge
* All the above on iOS, Android, Windows, Mac, Linux and WebRTC.