https://www.cnet.com/news/siri-vs-alexa-vs-google-assistant/

Connect your call to a HomePod via the audio button.

On the HomePod, unlike the iPhone, Siri can't differentiate between voices. That means anyone who says "Hey, Siri" will elicit a response from the Apple smart speaker. In contrast, both Amazon and Google smart speakers have voice training capabilities. With voice training, your whole family can use the speakers, but each of you can also get customize responses (and perform custom actions, like making purchases) based on who the speaker is talking to.