I cannot help you with reading comprehension; I cannot hold your hand till the end of an article that causes you cognitive dissonance.
Here's an analogy for you: if I criticise the fashion industry for its use of sweatshop labour, it is your ethics and not your fashion sense that I'm deriding by association. You want to hand-stitch shoes for 15 hours a day in the privacy of your bedroom, knock yourself out. It won't hurt the coerced or non-consenting, and it will have no flow on effects on society. This article is not about your bedroom practices.
(Do you understand that not all pornography features people who enjoy such acts, who gave their consent, and that they are not performing such acts with trusted partners but rather on set with strangers in the majority of cases? That they do not dictate the content of the videos, the director and producers do? It seems rather different from the tenets of BDSM, as far as I understand them.)
The article is clear on the study author's definition of violence, and why it counts all forms of (increasingly common) sexual aggression: from spanking that may not be injurious in the slightest to practices barred by the Geneva convention.
The article does not conflate adult and child pornography except to say that consumers are often watching the latter which they think is the former, and that both are hosted on mainstream platforms. The sexualisation of minors in adult pornography is reprehensible, and reflected in increased in sexual offending against young teenagers.
The article has nothing to do with gay people whatsoever, so spare me your outrage.
The article is about the empirically and sometimes experimentally verified link between non-consensual violence and pornography consumption, it is about getting people to question if any level of brutality is acceptable as long as a sex worker is paid, and it is about pointing out that not all pornography features of age, consenting participants. This all should be very easy to grasp.
Some pornography features women gritting through abuse to keep them off the streets or securing them future work, some is the video record of the rape of children, sex trafficking victims, or porn performers who are not immune from the violation of their boundaries, all for the sake of profiteers and apathetic or oblivious consumers. You seem to think BDSM videos are a reflection of the perfomer's desires and personal boundaries, that's naive.
My article explores an uncomfortable reality, that the consumer needs to start thinking about, and putting above their temporary pleasure. Treat it as food for thought, rather than moralistic judgement. Cheers!