I think the difference is chromecast and firestick use spotify connect (pull directly from server). When I send via bluetooth my ipad does whatever audiology AAC processing apple applies. Aparently I like it more? Not sure what they are up to.

I figure even a newer bluetooth DAC has got to be a little better than the old setup.... with aptX or Sony’s LDAC version onboard.

Spotify is capped at 356kbs or so. Probably over thinking this....