This doesn't in any way solve the problem of getting traffic in/out of the country, where all local ISPs are legally obligated to singlehome themselves to the government ASN.
Unless we're talking about something like smuggled two way satellite terminals.
Why go for LTE when Wi-Fi is so much more feasible?
I mean, 10 bucks for an AP isn't far fetched whereas LTE antennas alone would explode in budget, even when considering to use OsmocomBB with super old hardware/phones.
And every phone these days got Wi-Fi anyways. Most meshnet solutions rely on Wi-Fi so you wouldn't even need to implement much software for peering.
Hacked femtocells? SDR? Something more clever?
Distribute eSIMs to everyday people.
The pirate operator takes all the risk and technical difficulties.