The HomePod is a horrible device unless you want Siri in a can. The source selection is just so locked down for whatever reason, so unless you're all in with the Apple ecosystem, you're going to be missing out something.
The HomePod would be a incredible bargain even if it didn't support Siri at all, and were just an AirPlay compatible speaker. Everyone who complains about Apple Music (myself included) and Siri's uselessness are mostly ignoring the fact that it is the single best compact speaker, audio-wise, shipping today. It's an order of magnitude higher audio quality than everything within 10%-1000% of its price range.
It's insanely great. As a speaker. Period.