Yeah but then you have to trust the hardware of that device, which is harder to inspect than your average PC.

For example it can easily be detected if your PC processor has weak RNG, by generating a lot of [0,1] and measuring the probability distribution, it should be Bernoulli Distribution with a mean of 0.5 or with a very very small deviation from it , and the residuals should be 0 or very small over a huge sample.

How do I test the quality of the RNG in those hardware devices? I should just take their words for it?