Yeah, and guess how much time are people spending on their Smartphones vs time spent on average on a PC ? That should be fairly obvious that the number of minutes of usage per device is greatly in favor of computers vs smartphones. Smartphones are a fashion trend: people like to change them all the time when new models come out because there is a great technological advance currently on their specs. The same is not true on PC anymore, yet they are still selling by truckloads. Utility wins.

Dismissing smartphones as a fashion trend seems naive. There is a segment of PC users who emotionally react to the suggestion that the "PC", in reference to a box sitting on a desk, is in its twilight. I think it's due to a fear of losing mastery over the system.

PCs are horrendously complex for what most people would use them for--taking pictures, browsing Facebook, watching movies, and so on. It's no surprise that, as mobile devices have made these things easy to do, PC sales have been on the decline.

its a valid concern. basically you want all the economies to thrive so new things are being created by new players and everything remains affordable. and a healthy level of openness and modularity is so important too.