I found 75k for such a severe security issue a low figure, on apple security bounty page the max pay for such exploit is 500k.
https://developer.apple.com/security-bounty/
I imagine that a Black Mirror type of scandal involving this exploit could do many millions if not billions in damage to Apple’s finances. Not to mention what such an exploit might fetch on the black market.
They’ve just gotten used to banking on people taking much less than black market value in order to avoid legal complications.