Comment by nicoburns

For me the best solution would be seperate environments with completely different UIs, but running on the same device (probably in a phone form factor)

Apple's in the best position to offer this because they have both Mobile and Desktop OS's. And their chips are already capable of having two OS's installed side-by-side with a strong security barrier (and also more than fast enough to run a full desktop OS). But alas they haven't attempted it yet.