Yeah, while you might theoretically be able to build a national 5G network using this, it would be way more expensive vs just building it yourself. Amazon wouldn't be marketing this if they didn't expect to have a healthy profit margin, after all.

This seems more applicable in cases where you need 5G but there is no/insufficient 5G already, when it would be prohibitively expensive to go to existing carriers (mobile data rates in the US are ridiculous), or when the threat model necessitates a private network.