We can't enumerate these things (for obvious reasons), but I would be shocked if the overwhelming majority of onion services active any any given moment were anything other than nerds who need quick and easy NAT punching. By traffic volume, we already know the majority is just Facebook's onion services, then presumably followed by the NYT, BBC, etc.

I agree that more applications should make (transparent) use of them, but the whole "darkweb" aspect has always been overstated.