The offering from Hetzner I find especially appealing are the consumer grade hardware ones. No I wouldn't host business critical services on one, but I don't have those so easy win for me price wise.
I would probably host even some business-critical services on Hetzner's infra. I'm thinking of "worker"-type workloads, where each machine is 100% stateless and just serves to do some compute-intensive work. With that configuration, single-node data loss doesn't really affect you, and the CPU is plentiful and cheap with Hetzner bare metal (e.g. AX101 AMD machines).
Yeah, but where would you store state? The hyperscalers give you pretty reasonable durable storage (even datalakes). Most people don’t get storage tiering or using PaaS for workers, though.
I'd shy away from storing any non-volatile state on Hetzner. As I said, I'd mostly consider it for stateless compute-bound applications.
If I was looking to scale up an existing operation considerably and minimize costs as much as possible, I'd consider spinning up e.g. a Postgres cluster or minio on their infra, which would be significantly cheaper than RDS or S3. But it's not something that I would gladly do---the storage deals provided by hyperscalers are quite reasonable, as you say.
