It doesn't help that Apple doesn't let third party developers use it. The only SDK available for Homepod, is locked behind a bunch of approvals and the only thing it does is allow developers to implement music players. It's very specific to playing music. Not even Podcasts.

Why can't an eCommerce app implement, "Hey Siri, tell Online Store to add Tidepods to my weekly order". ?

What about Audible implementing, "Hey Siri, tell Audible to add Tale of Two Cities to my reading list." ?

There's remnants of a car service interface that never got used or shipped AFAIK. If you ask "Hey Siri, get me an Uber to the train station". It just replies "sorry, I help with rides".

Or maybe even work with other Apple stuff better. I can say "Hey Siri, turn on Television" and that works and then say "Hey Siri, mute television" and it will reply, "There are no televisions to control".