Less market concentration. Lina Khan, the current head of the FTC, argued before she got the job that market concentration and not consumer harm was a better target for antitrust enforcement.
Amazon does exercise a fair amount of their market power. FBA policies are generous to the consumer and to amazon, taking it out of the third party sellers. The other classic example was IIRC diapers.com which was a sharp competitor until Amazon bought it and raised diaper prices. It's possible this was all a ZIRP fad, and diapers.com was burning through investor cash, but still a pretty clear-cut case of consolidating market power (at the time the FTC did not consider it illegal).
Amazon does exercise a fair amount of their market power. FBA policies are generous to the consumer and to amazon, taking it out of the third party sellers. The other classic example was IIRC diapers.com which was a sharp competitor until Amazon bought it and raised diaper prices. It's possible this was all a ZIRP fad, and diapers.com was burning through investor cash, but still a pretty clear-cut case of consolidating market power (at the time the FTC did not consider it illegal).