comment history keeps taking aim at Proxmox. What did you find questionable about them?
Here's the thing, I run Promox since 2009 until the end of last year professionally in datacenters, multiple clusters around 10-15 nodes each. I've been around for all wins and fails of Proxmox, I've seen the raise and fall of OpenVZ, all the SLES/RHEL compatibility issues and then them moving to LXC containers.
While it worked most of the time and their payed support was decent I would never recommend it to anyone since LXD/Incus became a thing. The Promox PVE kernel has a lot of quirks and hacks. Besides the fact that is build upon Ubuntu's kernel that is already a dumpster fire of hacks (waiting someone upstream to implement things properly so they can backport them and ditch their implementations) they add even more garbage over it. I've been burned countless times by their kernel when it comes to drivers, having to wait months for fixes already available upstream or so they would fix their own shit after they introduced bugs.
At some point not even simple things such as OVPN worked fine under Proxmox's kernel. Realtek networking was probably broken more times than working, ZFS support was introduced with guaranteed kernel panics and upgrading between versions was always a shot in the dark and half of the time you would get a half broken system that is able to boot and pass a few tests but that will randomly fail a few days later. Their startup is slow, slower than any other solution - it even includes daemons that are there just to ensure that other things are running (because most of them don't even start with the system properly on the first try).
Proxmox is considerably cheaper than ESXi so people use it in some businesses like we did, but far from perfect. Eventually Canonical invested in LXC and a very good and much better than OpenVZ and co. container solution was born. LXC got stable and widely used and LXD came with the hypervisor higher level management, networking, clustering etc. and since we now have all that code truly open-source and the creators of it working on the project without Canonicals influence.
There's no reason to keep using Proxmox as LXC/LXD got really good in the last few years. Once you're already running on LXC containers why keep using and dragging all the Proxmox bloat and potencial issues when you can use LXD/Incus made by the same people who made LXC that is WAY faster, stable, more integrated and free?
I’m not uninterested in genuinely better alternatives, but I don’t have a compelling reason to go to the level of effort required to replace Proxmox.
Well if you're some time to spare on testing stuff try LXD/Incus and you'll see. Maybe you won't replace all your Proxmox instances but you'll run a mixed environment like a did for a long time.