[doute]

That is part of it. But the important point is that it is not inherent. There nothing saying that you can't be protocols for that. It is just beyond what the Internet was design for many years ago, and the de facto Internet today include proprietary infrastructure run by large tech companies. But it is generally even worse then that because today smart phone don't have external ip addresses so you can't connect to them even after the initial centralized wake up. So it is an absolute regression as well.

[Nextgrid]

Mobile networks are moving towards IPv6 now, so phones are uniquely addressable again. Making them reachable from outside (if they aren’t already) is a trivial problem to solve should there be demand for it.

But I don’t see any major use-case for that - the main issue of battery life remains for any significant usage, and frankly I wouldn’t want to have something running in the background that would deplete my battery in an hour because someone happened to connect and watch a video hosted on it.