there is a bit of talking between devices that happens in the background
Learn how Siri responds when there are multiple devices.
support.apple.com
If your phone screen is on and unlocked, the phone will take priority.
if your phone is face down on the table, it won't respond at all.
That being said, I wouldn't
I like the sonos system much better, especially if you've got a sound bar, as the direct wired connection is much more stable than a wireless one.
And I like being able to control music no matter what device I'm on.
With HomePod, if you start music from your phone, you might not be able to do anything from your Mac, with sonos, this isn't an issue. Sonos also allows others that use android to control the system.