That's because pass-through is still something quite experimental, it needs a specific matching HW stack and even then it can make problems. So the "working out of the box" config isn't really feasible at the moment, as there are different set of workaround people need. This would mean a lot of work for then not even help many, as there's no way we can test and preconfigure all possible HW/OS combinations.
Note also that Proxmox VE is mainly targeted for enterprise server use, the HW used there is quite different.
That's what the create wizard and OS settings is there for and already does some automatic adaptions to a certain degree.
I'd not call this "templates" in "Proxmox VE talk" but rather default settings.
If there's something which every GPU pass-through VM needs we're open to adapt that, but AFAIK we do the common sensible stuff already.
For the rest there are quite a few good tutorials and how to articles and videos out there, and IMO their better suited to address this for now.