I’m not sure what specific Sonos speakers you have, but all current Sonos speakers are airplay compatible.  Meaning you can send audio to Sonos speakers via airplay, the same way you would send audio to a Homepod, without using the Sonos app.  

You are also locking yourself into the Apple ecosystem if you go with Homepods.  You can only get TV audio through AppleTV, not directly from the TV.  I’m not sure what audio quality you can with Homepods from different streaming services, but it’s always going to favor Apple music over other services.

I also think Sonos is more invested in this market and looking to innovate more (partially why they got in this mess to begin with).  They have a new speaker tech they’ve been working on, and rumor is that it could be released in a new soundbar this fall.  That’s not to say that Apple doesn’t innovate at all.

It’s obviously your decision.  I guess I would say that if you are happy in the Apple ecosystem and what they have to offer, then it make sense to stick with Apple.  If you want to stay open to what other companies have to offer, than look around  and either stick with Sonos or see what other competitors have to offer.  The important thing is to know what you want/need and get what works best for you.

Thanks Danny, I was not aware of the Airplay feature. That is very helpful.

To my ears, for listening to music at least, an Apple HomePod pair sounds much better than a Sonos Arc with subwoofer.