goodlistening64
... TCP is reliable, but audio is packaged within the UDP (user datagram protocol) which has RTP (real time transport protocol) running on top of it. Audio is sent via UDP because it is faster and does not require a "handshake" on the other end ...
I'm not sure which services you're referring to here. Certainly, hi-res services such as Qobuz and Tidal are using TCP-IP for bit perfect transmission to your streamer.