From my understanding (I may be wrong), rent-seeking in the economic sense is not literally about receiving payment to loan another party an asset (e.g. car rental), but about engaging in zero-sum or negative-sum economic activity.
For example, patent troll companies would be rent-seeking because they don't create any value for other participants in the economy (except for perhaps lawyers!). Amazon's primary retail business could also be seen as rent-seeking to an extent because their massive market share essentially forces businesses to sell through their platform and give them a 10-15% cut of the sale.
AWS, on the other hand, is (or at least was) a genuinely innovative solution to people's problems. It gave small organisations access to supercomputers at affordable rates, in a non-monopolistic way, and in turn created much more wealth for the broader economy than Amazon themselves extracted through AWS fees.
