usage of this feature - business value

[Newpaw]

Hi, could you please explain to me the business value of this feature? Asterisk alone is able to use the WebRTC project. So why I should use both Janus and Asterisk at the same time? I understand that the Asterisk is better suitable for phone calls and Janus mainly focuses on audio/video streaming. When I should use meetecho/asterisk-opus.