...soon you will have just one device that does everything.
That's already true, for people who only have a phone. In the long term, it's completely wrong. Today's "super"-devices will explode into a constantly-changing constellation, as soon as personal networking is ironed out. Future generations will laugh at caricatures of people today, who constantly tend to and obsess on one hunk of plastic to the exclusion of the wider world.
Sure, but part of the process of "ironing out" local networks will be an easy way of categorizing what host gets what sort of connection to the internet. A pedometer built into a shoe needs very little access to anything.
In general one would say that, but there would be a category of local host that would mean "we don't trust this device to correctly update its firmware, so that action (and consequently most other network actions) is not allowed".
That's already true, for people who only have a phone. In the long term, it's completely wrong. Today's "super"-devices will explode into a constantly-changing constellation, as soon as personal networking is ironed out. Future generations will laugh at caricatures of people today, who constantly tend to and obsess on one hunk of plastic to the exclusion of the wider world.