I would like to use a Raspberry Pi as a presentation PC connected to a TV.

Presenters should be able to see the RPi's screen mirrored to their laptops while controlling the RPi directly via wireless keyboard/touchpad.

This way they can face the audience while interacting with the RPi/TV screen.

Ideally, this would work through the browser without installing any app.

Is this possible on Raspbarry Pi (or similar mini-computer)?

VNC, Guacamole and NoVNC do not support hardware encoding.

Maybe webrtc?

https://cloud.google.com/architecture/gpu-accelerated-streaming-using-webrtc