The reason out of all the artists F95 has leaks of, Sleepy is probably the only person who actually makes an effort to track and take down leakers. When he finds them, he bans them. It is why you have people who have leaked content in the past, but do not do so on a continuing basis like so many uploaders do on F95. How? Well, you have seen the little image markers he makes a few pages ago, sure, that could be cleaned up, but we also know that he has employed Image Steganography to make it extremely hard to clean and remove. To the naked eye, you cannot see it, you got to use software that can find those markers and even then, that isn't 100% certain. The great Sei came up with a filter for Photoshop that cleans it, but again, just like looking for it, it wasn't 100% fool proof in removing them.
So subs don't want to risk leaking content lest they want to be banned because Sleepy is nothing, if not serious about tracking leakers down and leakers don't want to risk bans for people on threads who are ungrateful and demanding but I digress. If Sleepy was as popular as say Dandonfuga or Sakimichan, he would have no hope of tracking the leakers as there are plenty who share those ladies content, but Sleepy is a niche art and genre, so it makes it easier for him to do so and he has the will to back it up. So bottom line, leaks are few and far between for the simple reason that Sleepy hunts them down and drops the banhammer on their asses.
As for those who ask why people who are subbed still come here to this sub, well two reasons I would say - A) F95 isn't solely about Sleepy content. F95 hosts a variety of artists and topics people are subbed to. Sure they could unsub to this thread since they don't want to risk being banned by Sleepy by leaking, but and this leads into my second reason and I speak of this in my own opinion, people like to shoot the shit with other sleepy fans, bounce ideas and thoughts on Sleepy's twisted little world of lesbian bdsm. We used to do that all the time in 8muses and it made for some interesting debates, just ask anyone who was there when Sleepy decided to draw the Putz getting pegged for the first time in Sleepy's content history and whether that constituted being gay. The mods had to come back and clean that thread up multiple times, it got that heated lol. Fun times.