sooo theres no way of preventing ur phones storage from being copied. it has to be stored on a chip somewhere, and that chips contents can be copied.
there is however a different way of protecting the data.
a strong encryption password is the only real protection against this kind of attack. modern phones have a chip called a Trusted Platform Module, that is capable of storing secret keys in a way thats very difficult to get to even with physical access to the device.
the way i understand encryption on modern phones, is that ur unlock PIN is passed to the TPM, which then passes a secret key (longer and more complex password than ur PIN) to the system to decrypt ur files.
this way, if u only copy the phones storage, u will have to bruteforce this very complex key thats stored in the TPM. or u would have to try to hack or brute-force the TPM itself, which is hardened against those types of attacks specifically.
having said all that, idk if its even reasonable to expect a phone to ever be secure against targeted government agencies attacks. best protection is not having anything personal on ur phone in the first place. so set disappearing messages on messengers, etc.
TL;DR use a long pin or a strong password for ur phone and try to remove any incriminating information from ur phone as soon as its not needed there anymore.
this does not seem to be an alternative to the existing method of profiting from ads etc., but more of an additional way to make loads of money