Lets say, hypothetically, that there did exist some trustworthy VPN provider, one that behaved in a way that you would approve (where, if you had unlimited time

Lets say, hypothetically, that there did exist some trustworthy VPN provider, one that behaved in a way that you would approve (where, if you had unlimited time and access to the internal operation of the provider to evaluate it, then you would eventually be convinced that it's "good", as good as reasonably, humanly possible). So assuming it exists, what would it look like? What would you see that would be positive or negative signs?