All AudioSources to Audio Mixer (listener to mixer group?)

Is there a way to send ALL audiosources to mixer Master group? Like all audio that is heard by audio listener to get processed through one group? Like in any audio system (cubase, protools etc.) all audio is send through master channel by default.

I have a lot of audiosources created via script. Isn't there an easier way to send ALL audio to the master group apart from .outputAudioMixerGroup = mixerGroup in all sources in script?

Why isn't there a way to send everything the audio listener hears?

Thank you.