Well exactly. Creating smartphone in 80s with vision of smartphone from 2020 would not work, because that technology was not there. It would be big, heavy, expe

Well exactly. Creating smartphone in 80s with vision of smartphone from 2020 would not work, because that technology was not there. It would be big, heavy, expensive, mostly without software and basically without connectivity. Look at AR/VR today - big, heavy, expensive and without use-case which would be interesting to masses. But let's move 20~50 years into future - AR/VR can look like ordinary glasses and cost like cheap smartphone today and you are controlling it by your mind. That's something what would have lot of interesting use cases.