It's not. Airlines do not make their money price discriminating economy customers over the same route at the same time.

Dynamic pricing is mostly a seasonal and timing game. And the actual money is made in higher classes of service.

This idea that Bob and Alice are shown drastically different pricing for the same seat because of insights into their specific purchasing behavior is just ludicrous.

Most people buy tickets from aggregators who have been already gutted the ability to do this anyway.