Sonos sells speakers that don't have any alexa or google integration.
says "Google Assistant" and "Alexa Built-in".
Maybe your threat model doesn't allow any hardware with a speaker that has updates, but that's not a reason to say it's an invalid setup for everyone's threat model nor to claim that, even without evidence, it's definitely going to be abused.
You could have taken a look round the site rather than just looked at one product...