If you're bursty and only run 1000 invocations every few days or weeks and otherwise you run it 0 or 1 times per increment then you can end up spending a lot less than that estimated server cost with fly.io no?
Definitely there will be cases where it makes sense. But intuition would suggest if your servers are say 80% idle then serverless functions would be cheaper, but that isn't actually the case. Cloud companies don't incur much of a cost from a VPS either if it's idle.
My team noticed the same with AWS Aurora Serverless (a database), it was so expensive that it was easier to just run a normal instance of RDS.
My team noticed the same with AWS Aurora Serverless (a database), it was so expensive that it was easier to just run a normal instance of RDS.