Why not just raise money to pay for service from for-profit providers? Much more efficient use of donation funds.

Hmm, I actually didn't think about that at all. I guess I got too fascinated by this video[0] and wanted to apply something similar to our current scenario.

[0]: https://youtu.be/lEplzHraw3c

Because often enough there is only one dominant service in the region who has no pressure to compete from anyone due to regulatory capture (esp. regarding right of way on utility poles) and so has no incentive to upgrade their offers to the customers.

If you intend to start a facilities-based last mile access ISP, what last-mile tech do you intend to use? There's a number of resources out there for people who want to be a small hyper local WISP. But I would not recommend it unless you have 10+ years of real world network engineering experience at other, larger ISPs.

There's a bunch of guidelines for starting a (W)ISP depending on your region.

I actually tried, but all I got was some consultancy services that would help you get an ISP with estimated cost of 10k USD (a middle class household earns half of that in a year here).