I see some CPU and memory usage on my setup... but I don't even see any IO!
Literally, the IO chart for "week (maximum)" on Proxmox for my Nextcloud LXC container is 0, except for two bursts, of 3 hours of less each. (Maybe package updates?)
The PostgreSQL LXC container has some more activity (but not much), but that's backing Nextcloud and four other applications (one being Miniflux, which has much more data churn).
You need two drives for the OS, four for data. Hetzner boxes are cheap with 2 drives, cost multiplies if you add any other.