I agree with you about tablets but not about smartphones, some people back then, this in 2006, were discussing just how smartphones would be the future once they became cheap, this is what happened.

Besides everything being touch based, which was really disruptive, I believe a real disruption in the iPhone was that it included a full browser and not the mobile crap that existed back then, apps were good, but it was something that existed in other smartphones although without the centralized distribution medium, but they did exist.

Now some people are saying that Apple reign will not last just because smartphone prices will follow the same path that feature phones prices walked in the last 10 years, they will become much cheaper than now, I do not know about Apple remaining the leader or not but I do believe that smartphone prices will be really cheap in 2020, even for developing nations.

EDIT: typo and correction in the last paragraph.