Also, it’s backed by a commercial business, so it’s likely to see continued support and dev. With the recent shitshow with VMware, I suspect it’ll be a choice for many businesses - which hopefully translates to a growth in user base (and financial support).
That’s kind of the problem with Proxmox, you never know when they’ll start requiring a license for everyone and what prices will look like. That’s one of the reasons why I’m telling people to look at LXD/Incus. It’s truly free/open and financed by the linux containers initiative that gets resources from multiple big vendors and providers.