It's about scaling. Google's offering is a cloud service and Hetzner's is not. You're always paying the same amount per month with Hetzner, whereas you'd only pay that much with Google if you have consistent full utilization (which seems rather unlikely; most workloads do not look like this). Secondly, if you create something that becomes popular, you can scale it up on GCE a lot more easily than you can with a dedicated hosting provider.