Earlier quoted context omitted.
Release the source code and provide some mechanism for users to have verifiable proof that the published code matches the application running on the device and we can start talking about trust. Given past track record of both companies, this is the only way I would ever have of not being skeptical.
Do you have some evidence that Apple and Google run backdoors to privacy on iOS or Android devices? You speak about the track record of both companies, surely you should be able to point out several examples of this. The spec seems pretty clear - it's not possible. If you feel that you don't trust them to implement the spec correctly due to incompetence or malice on their part - you need to supply the proof. If we're…
Even against their will, companies with capabilities can and have been compelled by government agencies to go against their promises and lie about it.
Additionally, with organizations of this size, it's very plausible that the vast majority of employees and even executives are blissfully unaware of wrongdoings, abuse and involvement in conspiracy by individual employees or decision makers.
All it takes is a single compromised or malicious person to add new capabilities in an update to an already rolled-out and well-intentioned software. Possibly a handful if you add strongly enforced and audited mechanisms for co-signing releases and whatnot.