sharing information while controlling who gets to see it, who does not, making sure it is timely, making sure it is gone when it is no longer timely, and making sure all of these things continue to be the case is still a problem more than six _centuries_ after the invention of the printing press.

Heck, it's still a problem with direct connections. Take the average Windows PC. Take the average Android phone. Take a USB cable. Plug them in together. Now copy a few thousand MP3s from the PC to the phone using nothing but stock Explorer and watch the transfer rate drop to about 1/1000th of what the wired connection should be capable of, because Microsoft made sure to assign their most inept, incapable, dumbest employees when they designed MTP.

Well, the Internet everyone uses isn't really designed for it. HTTP is a request/response model. But the model of filesharing is that I have a bunch of data and I want to send it to you, not that I have a bunch of data and I want you to ask me for it.

File sharing over the internet means setting up a webserver, after which it works beautifully. But nobody wants to do that. They want to use browsers.

TCP isn't asymmetric in the same way, but who's out there thinking of raw TCP as "the Internet"?