It seems to me that when people talk about what you ‘can’t’ do on a device, there are actually two different meanings of ‘can’t’ in computing. There is ‘can’t’ as meaning the feature doesn’t exist, and there is ‘can’t’ as meaning you don’t know how to do it. If you don’t know how to do it, the feature might as well not be there. So, there is what an expert can’t do on a smartphone or tablet that they could do on a PC. But then there are all of the things that a normal person (the other 90% or 95%) can’t do on a PC but can do on a smartphone, because the step change in user interface abstraction and simplicity means that they know how to do it on a phone and didn’t know how to do it on a PC. That is, the step change in user interface models that comes with the shift from Windows and Mac to iOS and Android is really a shift in the accessibility of capability. A small proportion of people might temporarily go from can to can’t, but vastly more go from can’t to can.