Problem with glove liners is that you still have a pair of wet gloves to contend with. You can get dedicated waterproof gloves, but unless you live in the PNW, you'll only get caught out in the occasaional rainstorm or rarely need to ride in the rain. Overgloves make sense, just like a rainsuit.
Don't have overgloves, but they just went up a notch on my "round-tuit" list...
'73 R60/5 Toaster