>The point is really that a lot of people are intimidated and compliant and will hand a device over when requested. This is never a good thing. Even if you’re legitimately a victim, you shouldn’t even let them at your stuff.

That's addressed by the OP

>People spoiled by western TV shows may talk about probably cause, privacy, rights etc. (which may exist on paper in these places too), but you’d be in a lot of trouble if you’re not very rich and know powerful people. These checks can also take an ethnic or other angle where only certain people are stopped.

There's a strong legal system (eg. due process, habeas corpus) that protects you in uk. No such system exists in Russia. Similarly, if you tried pulling this in china, and you're a Uyghur, that's just going to end up with you in a reeducation camp.