The least two features the average user wants. Most users are happy if sound and video work instantly, always. Maybe some marketing department should focus on that?
(Don't know keet; yes, encryption is still an important festure).
Peer to peer makes it as fast as possible because it's not having to pass through a 3rd party's servers (which, for cost reasons, normally limit the bandwidth of the communication channel they are serving).
This is just like when you pull down a torrent. You can do it as fast as your bandwidth and the bandwidth of the peers who are seeding it to you allow. Which can be blazingly fast.
[1] https://keet.io/