It is depressing. Networks are broken to the point where we have services resold back to us to provide the basic functionality that should be inherent in the protocol.
It is inherent in the protocol, but providers are more than happy to deny you the option to use your local connection to host services and NAT took away the peer-to-peer nature of the internet before it really took off.
UPNP and some other firewall traversal tricks restored some of that but asymmetric bandwidth is the norm these days. Maybe with IPv6 we'll see a reversal of these trends.
Exactly my point. Dropbox shoudn't even exist as a business model.
edit - not crapping on dropbox particularly. Lots of things should be basic functionality by this point, sharing files being one of them. If stuff was more like plan9, for instance, things like skype wouldn't exist either.
Required? Perhaps not. But we "should" definitely have the option, and it should appear seamless on other devices with which we share files whether they're getting them from our own machines or from a private encrypted cloud cache.
See: https://www.fourmilab.ch/documents/digital-imprimatur/ (prescient and very depressing read, but read it anyway if you haven't done so).
UPNP and some other firewall traversal tricks restored some of that but asymmetric bandwidth is the norm these days. Maybe with IPv6 we'll see a reversal of these trends.