That's a fair comment. But I believe the number of these is probably a small percentage given the size of the stores (at least for Apple). At least in the case of my mother, she has somewhere to go to when there is a problem.

I am not discounting the personal computer as a utility, but app stores and restrictions for some are not a hinderance either. With a mac (I am not sure about windows, I gather with ARM it is not possible), the ability to be in a hybrid mode suits most cases.

A mobile device at least from an Apple perspective is not a general computing device. Android on the other hand is more general purpose. But even with Apple's case there are ways to deploy your own app to your own device.

At least in the desktop space there is a choice, and it's not bad thing.