The whole Hangouts, Google Voice, Google Fi, Messages app is all a mess to me. As someone with various activity in all of these services I just have no idea wha

The whole Hangouts, Google Voice, Google Fi, Messages app is all a mess to me. As someone with various activity in all of these services I just have no idea what is happening. I wish there was a diagram explaining how everything breaks down alongside Google account / identity. There is some issue with RCS compatibility and using Messages for Google Fi. I just want the future to be here and tell me what I can/can't use and how.