What is the point of using Roll20 in Google Hangouts?

What does Google Hangouts bring?  Roll20 already has a built in camera and microphone system.

You can stream it to your YouTube account.

The in-browser video and voice sometimes causes havoc with some people due to resources needed. IE is not supported so, presumably, one could use hangouts with IE and get video and voice.

I much prefer using Roll20 through Google Hangouts because I get much less trouble that way . I'm in Australia and have players in Saipan and Florida. Hangouts works fine every time. The Roll20 audio doesn't give me that even if everyone is in Australia!

Hangouts for me seems to be more usable.  I prefer to use the built-in Roll 20 audio/video, and I do for some groups, but it seems that some players are not able to make it work.  I think it's always good to have a backup ready - just in case.

Also by using Hangouts you can integrate with Google Events, Communities, etc. and have the game schedule there with confirmations of who is going, do Hangouts On-Air for livestreams, etc. Some of that has been made a little harder with recent G+ UI overhauls but its still doable. There is also a very large community of Hangout gamers over on G+ that is also a good recruiting source.