I think a lot of people are missing this point. This will not allow someone to become their own carrier. It allows someone to install their own "cell towers" and have devices connect to them without having to use a 3rd party carrier.
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.
Yes I dont think OP's description is an accurate usage of Private 5G. Where it is aiming at industrial ( warehouse ) or cooperate usage within certain location ( cooperate HQ ).
Not sure how Tesla or Uber would get their own private 5G.
This doesn't seem to use AT&T at all, and amazon is actually bringing their own hardware too.
This isn't MVNO-aaS. Its Antenae-aaS.