There is no lack of examples of governments, currently and in the past, that do not ensure fourth amendment rights. Right now you can find countries where any evidence, no matter how it is collected or derived, is legitimate from the state’s perspective. They are not places where I would care to live.
Just my opinion, but I do not believe in the possibility, in the long term, of a state that possesses an unencumbered right to use evidence, regardless of individual rights, being benevolent in their use of said evidence. Power corrupts, absolute power absolutely. If probable cause becomes an illusion, if illegal searches and seizures are no longer illegal, why would we think that the state would only use that power against “bad guys”? How do they decide who is “bad” if there is no obligation for them to show probable cause?
I, for one, will not cede to the state both the power to arrest, imprison and prosecute AND the right to do so without regard to certain unalienable individual rights. That is a combination that is a formula for tyranny. Prosecuting police officers without keeping the state from using the evidence is, for me, a distinction without a difference. If the state is free to use the evidence, then they do so with effective impunity.
Accepting the fact that this may mean some of the guilty will elude justice is the price we pay for these freedoms.