Amazon's Alexa assistant, which is built into the Sonos One, lets me use my voice to play and control music from all sorts of music services, including Amazon Music, Spotify, Pandora, iHeart Radio, SiriusXM, and TuneIn. The Sonos One is even compatible with Apple Music, but that's without voice control.
The HomePod, on the other hand, doesn't let you use voice control for any other music service besides Apple Music.
If you want a speaker where you can control any of these services with voice control, the HomePod won't make sense for you. For example, I wouldn't be able to ask Siri on the HomePod to play NPR from iHeartRadio, like I usually do with the Sonos One, or ask it to play music from Spotify.