Back when we were spending 100k/mo on AWS, I calculated that equivalent infra would be $15k-$20k/mo at Hetzner.

A lot of those are spending 10-100k a month when they could be spending 1k-10k a month with a more lean infra

Why is that? I've seen couple of small firms using hetzner very successfully and saving a lot of money compared to whatever cloud offering.