Interesting approach. Not sure if they can replace the lean operations of most FBA sellers with an integrated company without compromising the profitability. Also FBA at scale is not necessarily cheaper then running your own logistics.
It's not a given that Amazon can run logistics automation better than you yourself, or a 3rd party.
At least in many countries other than USA, you would really need to have multiple logistics options for same products, and you almost always need that for cross-border.
Not saying their prices aren't competitive, for smaller volumes they very much are. Amazon is just milking their volume effects to a a max.