I stumbled across this and thought others here might find it as useful as I have:
https://localsend.org/
It lets you share files between devices on the same network, cross-platform. Windows / Mac / Linux / IOS / Android are supported. I've not tried the Linux client yet myself.
Transfer speeds aren't the fastest, but so far it's the easiest thing I've found to move files between my iPad, Samsung phone, PC, and Mac.