FWA seems like a lower cost alternative to FTTP -- until radio propagation constraints taken into account.

Outside of our urban cores and highway corridors, many modern life-enhancing technologies remain unavailable. For underserved constituencies, health outcomes are less positive; educational and business opportunities are more limited; and a myriad of other harms are borne by our more rural constituencies. But 5G FWA stands to finally connect those communities that remain unserved or underserved. Because this technology can span distances and cross terrains that coaxial and fiber cannot, at a fraction of the cost, more communities will be connected using 5G FWA than ever before. 

https://broadbandbreakfast.com/2023/08/sascha-meinrath-12-gigahertz-band-is-key-to-bridging-the-digital-divide/

The challenge is very limited propagation. The high frequencies used by FYA like the 12 Gigahertz cited in this article have very limited reach. Propagation distance is inversely correlated to the frequency. High frequencies can carry more data than lower ones. But the tradeoff is they don’t travel very far. Consequently, homes and businesses close to FWA radio towers get good throughput as Doug Dawson explains in this blog post. But just a bit farther out, it drops off dramatically as this example of a Sacramento, California suburb illustrates using two relatively lower frequencies. For 12 Gigahertz, the propagation circle of coverage would be even smaller. 

To overcome these limits, in rural areas it would seem to make sense to deploy radios close to customer premises mounted on existing utility poles or new dedicated poles. But the tradeoff there would be those radios would need fiber to feed them. At which the economics would point to connecting the premises to fiber directly as the most cost-effective approach.