As someone who paid for the best of those third party apps before… Apple has done a much better job. It’s not even close.

For example my iPhone can be turned off, locked, and in my pocket, but the camera is still discoverable and able to be enabled on all my Macs and even my TV. Simply select the camera like you would any other and put it some kind of mount.

The third party apps require quite a bit of mucking around to get it to work.