Torrents also don't provide encryption between peers, unless you use SSL torrents, but it's clearly designed towards sharing between a group, not one-on-one transfers.
It's just a bit more involved to use for this use case, especially if the data is confidential (having to set the private flag so clients don't publish the infohash to DHT, using a built-in tracker in your client, transport layer encryption not provided by default). Things like Resilio are fine, they build on top of the protocol and provide a different UX.
(BitTorrent/Resilio sync uses SSL and seems fine for 1-1 design-wise)