I have BT headphones paired to a nest hub max. I can command via the headset mic, that's good.

The Google voice does not come through the headset, the voice is only on the hub.

Eg; ok Google play classical music, hub says "playing classical music now'. This is a good thing if using Bluetooth speakers. If it's a headset to avoid disturbing other people during late night music listening, or if at long distance from the hub device, the audible hub voice is not desirable, the lack of voice in the headset is not desirable.