A quick observation on Voice Branding
This Christmas my little apartment swapped from being a primarily Alexa-led area to Google Home. The main reason for the switch was Google Home's better ability to distinguish between different voices and automatically associate the right Google profile.
Amazon forced me to say 'Spotify' all the time to get my music out of Alexa. The default music app was, of course, Amazon. I'd have to say "Alexa play 'Discover Weekly on Spotify'" to get that algorithmically determined collection to play. While Amazon was trying to relegate Spotify to a tier-two music provider what I actually noticed was that I was using Spotify all the time. It wasn't any harder to say the brand. Making me speak it just reminded me that I didn't consider Amazon's music offering good enough.
Google Home is different. I don't need to say Spotify and I can make it the default player. "Hey Google play 'Discover Weekly'". After a week or of this the fact that I'm paying Spotify to make this possible is easy to forget. It's Google that I notice. They're the brand I associate with my music solution.