I've clicked a few, and have chosen "teens" rather than anything else because one tends to get ladies who are "enhanced" or flabby, or otherwise less than "pretty" on other sites.
Yes, some of then appear to be less than 18, but the disclaimers, which are enforceable in law, say they are not.
I have no problem with pornography with consenting adults.
Some women, even young ones, are making large amounts of money from it, and are (I have read some surveys but can't, off the top of my head, refer any of them) apparently quite happy about their "career".
Some of them have become involved with pornography at about 18, and have gone on to produce their own pornographic sites, while still looking extremely young.
I really don't think that the enjoyment of viewing some young (over 18) ladies on pornographic sites has any great consequence.
Perhaps it might be better if the only images were "enhanced" or saggy breasted, flabby and obviously "professional" performers?
The fact is that they are performers, and some of them appear to be young.
What is the problem?
Should it be stopped, bearing in mind that those performers have to give evidence of their age?