If a commercial provider told me they're dependent on a single physical server, with no real path or plans to fail over to another server if they need to, I would consider it extremely negligent.
It's fine to not use big cloud providers, but frankly it's pretty incompetent to not have the ability to quickly deploy to a new server.
That being said, removing dependence on single hardware nodes isn't something you need a big team for. I've done failover at 1-person startups.
By increasing the complexity you multiply the failure points and increase ongoing maintenance, which is the bottleneck (even more than money) for volunteer-driven projects.
Kubernetes or complex cloud services are not required to have some basic deployment automation.
You can do it with a simple bash script if you need to. It's just pretty surprising to see the reaction to a hardware failure being to wait around for it to be repaired instead of simply spinning up a new host.