I don't think anyone is suggesting that smartphone ownership means you give up all hope of privacy.
You are trusting that your efforts to disable Siri and Cortana have actually resulted in them being disabled, and that Apple and Microsoft aren't doing nefarious things to keep them enabled anyway. If you trust that, I don't think it's a stretch to trust that Apple and MS would avoid doing nefarious things with a HomePod or [whatever MS's analogous device might be]. You seem to not want to have anything around that can record you without your express permission, so sure, I get why you don't have a HomePod.
I had an Amazon Echo for a while, but decided I didn't trust Amazon, and exchanged it for a Google Home. I have an Android phone with Google Assistant enabled, and I don't see the privacy implications as materially different between the two.
You are trusting that your efforts to disable Siri and Cortana have actually resulted in them being disabled, and that Apple and Microsoft aren't doing nefarious things to keep them enabled anyway. If you trust that, I don't think it's a stretch to trust that Apple and MS would avoid doing nefarious things with a HomePod or [whatever MS's analogous device might be]. You seem to not want to have anything around that can record you without your express permission, so sure, I get why you don't have a HomePod.
I had an Amazon Echo for a while, but decided I didn't trust Amazon, and exchanged it for a Google Home. I have an Android phone with Google Assistant enabled, and I don't see the privacy implications as materially different between the two.