In uncensored movies, sometimes, one shot can be few minutes when there isn't anything specific to change. For example, when they're using toys on a girl. She just has to act like she's getting excited. The actors around just have to use the toys one after the other. There are uncensored movies in which the actor uses the camera himself. So there are less cuts, still, the girl is acting for the camera. Like Danny D said in one interview, the goal is to make a good movie for the viewer. And on social media or interviews, of course they might say "oh yeah, porn actors are so good". It's marketing. Would you watch/buy a movie if the girl says "he was a douche, I wanted to finish the shoot as fast as possible". It's like fitness influencers saying they're natural (while if you have a brain, you can clearly see they're lying, just to sell their stuff).I know this is true in many cases, but I was actually surprised when I watched a few uncensored and unedited leaks by how continuous the action was. I had always assumed that most cuts in a finished film represented breaks in the action for the director to issue instructions etc. But it turned out in the leaks I watched that the cuts were mostly, as you mention, to make the transitions between camera angles smoother, but the fucking continued all the time the camera was switching to another view.
Another thing to mention is that editing (audio and video) is key to make everything like one smooth scene as possible. It's more appealing for the viewer.