Sadly, hardware breaks. You still need a working backup and a working failover plan, even if it's just setting up a new server and running your Terraform / Pulumi / Saltstack scripts.

I'm not sure if you read my post.

When you have 2 nodes running, both are mirrored and running, one can have hardware break.

Also, hardware can provide failure notifications before it breaks, and experience teaches to just update and upgrade before hard drives break.

Since tools like proxmox just add a node, you add new hardware, mark the VM for that node to mirror, and it is taken care of.

Terraform etc can sit below Proxmox and alleviate what you're speaking about:

Some examples: https://www.youtube.com/watch?v=dvyeoDBUtsU