It is with the amp which is hard wired but I find the Sonos Ones have pretty crappy WiFi or airplay implementation so don’t work as well. I just replaced a set of Sonics ones with two more Homepods for this reason. Plus the Homepods sound a lot better and Siri works very well with amazing microphones on the HomePod. Alexa on the Ones is pretty awful so you are better off using a dot.
Thanks for the feedback. I had a similar experience with airplay 2 to a sonos one and a marantz receiver (airplay 2 enabled). Good wifi at home but the sonos one had some occasional drops on airplay 2.