A soundbar, such as Sonos, with HDMI/ARC connection to the ATV will be the best solution.
You get wired/synchronized audio, and the HDMI/CEC controls (depending on the soundbar) gives you integrated control of volume and power on/off from a single remote.
Sonos creates its own wireless connection between their soundbar and additional rear surround speakers and subwoofer (if you choose to buy/use surrounds and/or subwoofer).
The only reason I can’t wholeheartedly endorse Sonos any more is because of the company’s huge problem with their app rewrite which they are still trying to dig themselves out from.
If you know, then fine, if you don’t, do a lot or research and set expectations that you are still effectively using a beta product.
On the positive side, the Sonos home theater setup you are discussing, using mainly soundbar and optionally rear surrounds/subwoofer, is very solid and doesn’t require the Sonos app for anything other initial setup.
A soundbar alone will give much better sound than any tv’s built-in speakers (law of physics - modern flat screen tv’s have tiny speakers and audio is all about moving air volume).
Soundbar versus a pair of HomePods (big ones, not little ones) is debateable. I feel the soundbar is still superior and as you have seen, single or paired HomePods (Big or small) rely on standard Wi-Fi for the audio connection which can be flaky.
Having said all that, if going with Sonos, avoid the entry-level Sonos Ray, it is junk. Sound is not great, and it connects with optical cable, not HDMI.
The Sonos Beam is ok, if on a budget a decent choice, but get the V2 generation.
The Sonos ARC is a little pricey, but huge improvement over the Beam. If budget conscious, consider getting the older Sonos ARC model, not the current flagship Sonos ARC Ultra. A few features will be missing, but most of us with Sonos ARC’s are not rushing to replace them with Ultra for only incremental benefit.
e.g. the new “AI voice” feature just announced that is supposed to do a better job of isolating dialog/speech versus the existing “dialog boost” that most audio gear has now.
P.S. Sonos is modular, so can start with just the soundbar and in the future add the rears and/or the subwoofer. Allows budgeting over a few years instead of all at once.