Desktop OS also don't support Dolby Vision or fancy spatial audio formats.

Trifecta: Piracy + Local media server + Streaming device, either Apple TV/Android TV (without internet access).

No loss of quality, devices that could spy on you, don't, and those that would spy on you, can't. The only trade-off is some convenience.

It does let you do that, but only on platforms where they can enforce HDCP. So e.g. Edge on Windows or Safari on macOS work fine, and I think Chrome recently joined the list too. But not on Linux.