They're massively more convenient. Dry herb vaporizers require me to reload the device every few hits and carry a supply of dry ground cannabis with me everywhere I go. The wet capsules last for hundreds of hits, and produce less scent both when in use and when inactive.

I've also found good capsule vaporizers to be more reliable than any of the four dry vaporizers I've purchased. But I have personally stopped buying black market vapes after I lost my supplier and the next few I was able to purchase immediately destroyed my lungs... :/