Neon is a lot more than just storage. It's branching, autoscaling, (cheap) read replicas, serverless computing, etc. If you only care about storage pricing, Neon is not the service for you. As you've said, storage pricing is cheaper elsewhere.
Sure, but I've got serverless computing with Aurora v2. I've got upto 15 read replicas, blue/green deployments, upto 128 cores per replica at a cheaper price... I'm just not really thinking that a bit of branching will make up for a 10x or more increase in cost.
Those increased storage costs make the decoupled compute and the associated auto-scaling benefits almost irrelevant as far as the overall cost picture goes.
We have former Aurora users come to Neon who tell us they saved money by switching. If someone like yourself were to migrate, they definitely would be an enterprise sale, which has different pricing than what is available in our current tiers.