I have some dot reticle scopes that I use for target and varmint hunting - they aren't Leupold, they are dots installed by T K Lee.
For target shooting, the dot needs to be quite small, and for varmints, too, IME, or they cover too much of the target. One or two MOA or one or two inch dots would be far too large for my taste. The dots in my reticles are either 1/4 inch or 1/8 inch. At that size, they don't cover too much of a varmint at even extended ranges.
However, there is a big drawback: as soon as light becomes even a little bit low (dawn and dusk), you'll have a hard time seeing the dots.
Small dot reticles do work very well for target/varmint in daylight, and many benchresters use small dot reticles, too- but they are a specialized tool, not an all around reticle, IME.
Mil Dot reticles are commonly seen, too, but, IMO, the dots on every one of those I've seen were vastly too large for varmint/target use.