Some smart guy wrote about this in his grammar book . . .
by notra_dahm (2021-04-01 08:25:21)

In reply to: Nit enclosed.  posted by PWK2


Common Errors in English Usage:

"very unique"

“Unique” singles out one of a kind. That “un” at the beginning is a form of “one.” A thing is unique (the only one of its kind) or it is not. Something may be almost unique (there are very few like it), but technically nothing is “very unique,” though this expression is commonly used to mean “highly unusual.”