I can not understand why I can not use an iPhone, as a webcam for a MacBook without third party tools (eg. epocCam), that require installation of drivers. To m

I can not understand why I can not use an iPhone, as a webcam for a MacBook without third party tools (eg. epocCam), that require installation of drivers. To me this is an obvious thing to do since Apple is so proud of its ecosystem. Especially in the time of corona when all the dslr / mirrorless camera manufacturers are releasing software to do just that.