They're a "real" cloud provider (with their own hardware) and not a reseller like Vercel and Netlify. So this isn't _that_ surprising. AWS economies of scale do allow them to make certain services cheap but only if they choose. A lot of time they choose to make money!

AWS is one of the most expensive infrastructure providers out there (especially anything beyond the "basic" services like EC2). And even though AWS still has some globally-notable uptime issues, "nobody ever got fired for picking AWS".

As a person working in a startup which used AWS for a while:

*AWS is expensive, always, except if magic*

Where magic means very clever optimizations (often deeply affecting your project architecture/code design) which require the right amount of knowledge/insights into a very confusing UI/UX and enough time evaluate all aspects. I.e. it might simple not be viable for startups and is expensive in it's own way.

Through most cheaper alternatives have their own huge bag of issues.

Most important fly.io is their own cloud provider not just a more easy way to use AWS. I mean while I don't know if they have their own server centers in every region they do have their own servers.

They run their own data centers.

AWS isn’t the cheapest so how is that a surprise? They are a business and know how to turn the right knobs to increase cash flow. GPUs for AI is one major knob right now.

Genuine question...why are you surprised?

It would be absurd if it wasn't.