Yes, this. Those here parroting Apple's "superior sound" line don't seem to get it. That's not really a killer feature with this type of product. It's not an audiophile device, and not priced as one either. It's geared to play compressed audio and use voice commands to control audio streamed from Apple Music. It does do some Siri commands, but not all. That's like a niche market of a niche market.
OTOH Echo, also not audiophile, doesn't market itself that way, easy to use, does all sorts of tricks, and multiple price points, none really outlandish that has attracted users to that platform. That is Echo's secret sauce. The only issue with Echo for me is I don't trust Amazon enough. But most people are unfazed or unaware on the security issue.
It really does baffle me that Apple is targeting HomePod for it's 30 million AM subscribers rather than it's hundreds of millions of device users. I mean all those Apple device users have had lots of time to sign up for AM but declined. Does Apple think a speaker more expensive than the Echo but with less features other than "superior sound" is going to convince the rest of us when that speaker with Siri can't do much else?