I have a pretty decent thermal spotter, Hikmicro Gryphon GH35. Frequently I have thought, thats a fox! Only to then confirm with my NV that its a badger on speed or a really pointy eared lamb.
Thermal is great for scanning, target acquisition and range finding if you have that feature. But NV will always give you a better picture, even if you spend the big bucks.
But the major factor for me is, I leave my rifle on the bonnet of my car, hanging off my sticks or on its bipod when prone. I then stand, sit or lay down and scan my arcs with the thermal. Do you want to scan your arcs with a rifle? Even a super lightweight rifle will soon become heavy doing this.
So for me I cant see myself ever using anything other than a Thermal spotter paired with an NV optic.