Gimmick... Google assistant will be better at helping you and I see future in it... Al these weird thing like Bixby, HTC's AI and Starbucks's AI are just to be there... Even Siri and Cortana won't have a future that bright... The single reason is that Google has the Internet, they know much more than Apple or Microsoft.
No point, without serious search engine it would be useless ... like Sir
Even with Google search behind is only mind useful.
In general few things are more gimmicky than taliking to your phone. It's useful sometimes, and that's it... nowhere near the utopian view of communicators of the future. Nobody really cares to talk to his device ... it's a device, why talk to it?