Do you know this or is this wishful thinking?
From what I understood, Covid Apps for Apple would not be able to send out the bluetooth packets while running in the background because the iOS design prohibits this (probably for good reasons? battery consumption?).
All Apple did was opening up an API to allow for exceptions of the old behaviour. That plus a cooperation with Google to make sure the tracing would work across iOS and Android (while Apple usually keeps their users in a golden cage not easily left for other systems). You make it almost sound as if common standards/protocols were a bad thing in general.
How much help would it be that anyone could implement their - potentially incompatible - solutions on their own? Ultimately failing because the OS wouldn’t let that happen (like Apps not being allowed to access the camera when permission is not granted, or not allowing Apps to read all data of all other Apps).