Hags don’t originate from prime material plane, they’re extra planar in origin; mostly fey which is tenuously linked, or fiendish which is not.
They’re interloping alpha-predators without a natural predator and deadly parasitic reproducers.
If you expand definition of natural too much, you lose definition. But that misses the point anyway; DND creatures are beings of story to suit heroic fantasy.
Now that said, unique hag origin story can upend this, but that’s exception proving the rule.
Imo, magically created owlbears which nonetheless fit into natural order should give Druids pause to think. Hags shouldn’t.
