OK, I can definitely see how your professional experiences as described would lead to this amount of distrust. I work in data centres myself, so I have plenty of war stories of my own about some of the crap we've been forced to work with.
But, for my self-hosted needs, Proxmox has been an absolute boon for me (I moved to it from a pure RasPi/Docker setup about a year ago).
I'm interested in having a play with LXD/Incus, but that'll mean either finding a spare server to try it on, or unpicking a Proxmox node to do it. The former requires investment, and the latter is pretty much a one-way decision (at least, not an easy one to rollback from).
Something I need to ponder...
Tossing in my vote for Proxmox. I'm running OPNsense as a VM without any issues. I did originally try pfSense, but didn't like it for some reason (I genuinely can't recall what it was).
Either way, Proxmox virtual networking has been relatively easy to learn.