Sometimes it's completely acceptable that a server will run for 10 years with say 1 week or 1 month of downtime spread over those 10 years, yes. That's the sort of uptime you can see with single servers that are rarely changed and over-provisioned as many on Hetzner are. Some examples:
Small businesses where the website is not core to operations and is more of a shop-front or brochure for their business.
Hobby websites too don't really matter if they go down for short periods of time occasionally.
Many forums and blogs just aren't very important too and downtime is no big deal.
There are a lot of these websites, and they are at the lower end of the market for obvious reasons, but probably the majority of websites in fact, the long tail of low-traffic websites.
Not everything has to be high availability and if you do want that, these providers usually provide load balancers etc too. I think people forget here sometimes that there is a huge range in hosting from squarespace to cheap shared hosting to more expensive self-hosted and provisioned clouds like AWS.