Do note that with dedicated servers you are subjecting yourself to things such as hardware upgrades and failures which you will have to manage yourself if you want to prevent downtime.

And while Hetzner customer support is generally excellent, in my experience, their handling of DDoS incidents will generally leave your server blackholed and sometimes requires manual intervention to get back online.

This is something you need to account for in terms of redundance if you are planning to expose your application directly to the net without any CDN/Load balancer/DDoS filter in place.

From my experience it makes sense to work with a data centre that is less focussed on a mass market but allows for individual client relations to mitigate risks like that. I love Hetzner for what they are and do host some services with them, but I wouldn't build a business around services hosted there.

And this not only goes for Hetzner but pretty much any provider whose business model is based on low margin/high throughput.