You’re not making an apples to apples comparison. You can run k8 on a single server or run 1,000 bare metal servers. Number of servers and how you deploy to them are tangential things and not mutually exclusive.

You seem to also be implying that by running a single bare metal server you have eliminated any chance of downtime which isn’t true

For example if your process crashes on bare metal, you go down, unless you have some kind of supervisor that watched and restarts the process, if youre not using kubernetes as a supervisor then you need to set one up using some other tool. At the end of the day you can’t eliminate all tooling/downtime.