This is well outside of the practical capabilities of anyone but a nation state or
large commercial entity. Even then, it's hard. It's more practical for a physical letter than for digital stuff. For a digital service, you'd have to go down to cabling infrastructure or take something like the SpaceX route and launch satellites. If you need something between a few nearby buildings, it's more practical to come up with a solution, but anything further out ... you're kind of stuck.
(Your ISP classifies as a middle man as well...)