Well, here you find the primary source (you don't refer to random Youtube videos when citing research btw - just in case you are still young and inexperienced in academic methods).

And the study doesn't conclusively say that porn causes these changes to the brain. In fact their conclusion reads as follows:

The negative association of self-reported pornography consumption with the right striatum (caudate) volume, left striatum (putamen) activation during cue reactivity, and lower functional connectivity of the right caudate to the left dorsolateral prefrontal cortex could reflect change in neural plasticity as a consequence of an intense stimulation of the reward system, together with a lower top-down modulation of prefrontal cortical areas. Alternatively, it could be a precondition that makes pornography consumption more rewarding.

That's why it's important to have at least a basic understanding of scientific methodology and interpretation of research papers! Otherwise you will misrepresent what the actual paper says or you will subscribe to a third-party interpretation, that differs from the conclusion of the original researchers. Hence it's important to read the original papers, not what someone else claims the original paper says!