Why do you think you need to touch them after deployment? You just pay the monthly bill. The thing is you can't just deploy and rest usually as there are often security concerns, your provider could run out of service, various system failures which require a restore of an healthy state or similiar. Even if you serve just static files, there could be the need to adjust your DNS, because the provider changed after 5 years something, or some other provider-related configuration. You really want to care for all those things at your frist deploy if you don't want to care for them long-term. The Hetzner firewall makes frequent security app updates mostly unnecessary, Ubuntu auto updates care for the security of the OS, the backups make recovery easy, if Hetzner goes out of service, you can restore your system wherever you want as it is just an Ubuntu server, by keeping only one app per server you also reduce the complexity of the system, separate the systems, so that failure can't spread.
Managing a server is nowadays with offerings like Hetzner the easiest way to run apps which just need to work and don't need to scale to exponentially over time. Why add anything on top of it? It's done really within 5 minutes if you know what you do.
If you need something which scales and doesn't require file storage / databases, then I'd go for the provider-agnostic Serverless framework. If you need storage and/or databases then it really depends, as Serverless gets costly at these things and more complex and there are more provider-lock-ins. Containers may make mor sense in such cases.
At our company we use these two systems to reduce maintaining basically to zero.