I don't think Amazon even needs experiments like this to increase its dominance.

Take the apartment complex i live in as an example, last year there was a marked increase in package thefts that the residents started complaining. The management came up with a few solutions that all got shot down, cameras were a straight no from most people because of privacy implications, increasing rounds by the security was also shot down since its a huge complex and it would require a lot more people (which they implied might lead to increase in rents in the coming years).

What did everyone decide on? on-site Amazon lockers. So now the choices are that you either buy from Amazon, or risk having your package stolen. Guess what everyone does now?