Airdrop is a feature that utilizes Wi-Fi protocols. What you describe is just Airplay (which also uses Wi-Fi protocols) but in the Airdrop menu. I don’t see the point I’m that when AirPlay and screen mirroring and extension (sidecar) works like you described.
As for the VR/AR stuff..it’s not out so there’s no telling how it will actually work. If it’s like the Oculus Quest with Airlink (Wi-Fi) to a PC, then it will work similar to what you described.