Proxmox is missing a lot of enterprise features. If you run a virtualized data center, it’s really not going to cut it. OTOH, if you are a small operation with just a handful of virtual servers, it might be “good enough”.
The obvious alternative was Hyper-V, but it looks like MS is already killing it to force people into Azure.
When you look at enterprise-level hypervisors, there really aren’t a lot of options.