Chia's nodes are not all running in the same data centers and owned by a single company like Amazon's. To imply that is disingenuous at best. They are operating all over the globe in independently owned data centers and people's private residences. Geo-location by IP will give a fairly good indication of that, but even just a simple survey of farmers from forums, chat, reddit, etc will give you a feel for the heavy presence throughout Asia, Australia, Europe and the US. Also, you can look at the number of unique pool public keys to get a feel for the ownership decentralization. (https://www.chiaexplorer.com/charts/networkDecentralisation) While not perfect, people do not tend to create lots and lots of pool public keys. Therefore, one can be relatively confident that the network has a high degree of decentralization.