Simple ftp isn't obsolete if you want a device to boot its operating system from the network.
Admittedly a niche application these days, but I've done it with linux as well as the
windows pre-installation environment.
Sorry, It's irrelevant to this thread.
I'd use any cloud service for sharing large files, most of us have access to one already via our phones.
Fair enough but indeed very niche and I'd stick by the description of obsolete for 99% of use cases and certainly anything over a public or even a large private network.
100% I would use a commodity cloud service. It can be quite fun to set up low level stuff for the sake of it but too much faffing for no reward and no small risk.