I bought an Apple HomePod, foolishly thinking it'd have some hardware inputs as well. Obviously that's not the Apple thing to do these days. But it has Airplay 2, so I figured there'd still be a way to interface with it easily. My macbook worked fine, but there was a 2 second delay for every input unless you used Siri.

Funnily enough, my Windows computer streams to the HomePod in real time, so now it's a pretty overpowered gaming speaker. But at least that's all it does; there's no bespoke Apple software that has to be installed and updated. And it's fairly dumb in terms of what you can manage with it (none of this stuff like yelling your shopping list at it.) Before I found that particular software, I was about ready to return the thing and switch to a Sonos... until I remembered what they were doing with legacy devices.

It would be nice to know if there's a way to build anything custom for it at some point though, since it's just a massive speaker with iOS inside it.

If you ask me, there should be regulations about providing a reasonable fallback when selling physical products that depend on some internet service to work. If the service is shut down, the device should be made functional without it (or with a custom thing you can host yourself).