How these youtube channels make money?

Today, I found some youtube channels on biographies about curvy girls/models and pornstars. These channels get millions of views per month. New channels like 3 months old get millions of views. I didn't find any ads running on them nor did I find any of affiliate link on their description. So how do they earn money on Youtube? Just curious to know.

Some channel names are:

Soft Model
Know Your Pornstar
TopXprime
InstaPop Fashion
DidSomeDigging
Fusion Tv
Celebs Wiki Info
Models Bio Info
ZaHo Insta Fashion

etc.

This kind of channels are often sold at the end, or they have a shop as we can see on "DidSomeDigging"

Some channels like this can also promote their monetized channels

Google adsense.

Does anyone know what tool they are using for voice over in Soft Model?

I checked TopXprime & it's monetized

I do not think they make money from YouTube since they will not be allowed, pornstar is not really OK with Google. YouTube also says the videos are age restricted so I doubt they make any money.