Also note: traffic costs. On Hetzner, it's almost impossible to pay for traffic. Even their tiniest machine has 20 TB outgoing traffic (and unlimited incoming). If you used it up (you most probably wont), that's another 1,792 USD of costs saved by your tiny 4$/month VM compared to AWS. (At least if I was able to use the AWS cost calculator correctly).

They will have object storage soon, but dont hold your breath for one-click kubernetes etc. So the fancier you infrastructure, the more you your startup would need to invest in time and money to use Hetzner and thus make it "not worth it".