In the common-practice style, usually dominant chords were always major, even in minor keys. Without the leading tone, how did minor dominant chords (v) function?
These minor v chords are not typically viewed as dominant in function, no.
Instead, they most often function as passing chords. Imagine we pass from i through v6 down to VI (or even iv6). In these cases the v chords very clearly do not reach the hierarchical level of a "real" dominant and instead are just voice-leading conduits leading from one chord to another.
They can serve a handful of other purposes (like as a pivot chord in a common-chord modulation), but their use as passing chord is far more common.