As expected Apple launched a competitor to Amazon's Alexa and Sonos' home audio solution as the HomePod. This Siri driven device integrates with Siri and HomeKit; and most importantly of all, Apple Music.
That could be a potential problem for sales though. Apple Music subscriber numbers are low and that could impact HomePod sales. The music streaming service which people want is Spotify - with more than 100m active users.
I guess the question is whether HomePod is good enough to be a carrot to persuade Spotify users to switch to Apple's service. Existing Apple Music users are likely to be Apple diehards anyway, so chances are they'll be buying a HomePod.
Spotify users - especially those on Apple - are going to be a much harder sell. Amazon offers significantly cheaper and more capable devices, which can be tethered to your existing home stereo system (yes, even Sonos) to match HomePod's musical abilities.
There's little motivation to make a change and that could hurt HomePod sales. That's probably not a concern for Apple, especially given the long term view of services as the future.
Which makes the purpose of HomePod clear: it's a defensive measure to keep Apple customers firmly locked in the Apple ecosystem.
In that respect the HomePod is a glorious success, giving one more reason for Apple customers to stay with Apple. It's not so much a question of creating a walled garden, more a case of making a garden so attractive you never want to leave.