Real time covers a lot of different things, and have a lot of different solutions.

Do you mean real time like games? “Wireless” headsets are perfectly fine and usable. Real time audio? Wireless transmitters and receivers exist and are used (granted with wireless in-ears but IMO that’s mostly so the don’t fall out) at the absolute highest level of audio production and live events.

You definitely can’t just say wireless isn’t used for real time.