We are pushing xxTBs every month at this point, and I haven't got the call yet. I'd have to spend $yyyy dollars on Fly.io for that kind of bandwidth. By simply moving to Unbound last month, we even halved our bills, and with some planned software changes, bills should go down another 30%. Besides, Matthew Prince says pushing higher bandwidth via Workers is fair game [0].

That said, I very much prefer Fly.io to AWS for workloads not suitable for Workers... and in just these past 3 months, we committed eng resources to make sure Workers workloads can run on Fly.io too, if and when the time comes for an instant migration.

We also run workloads on AWS AppRunner and Amazon Lightsail Containers and that's only because S3 <-> EC2 bandwidth is ~$0. We'd definitely move to R2 once Cloudflare opens it up, and we hope, eventually, Fly.io reaches the scale to peer directly with Cloudflare DCs for lower latencies, if nothing else.

[0] https://news.ycombinator.com/item?id=20791660