Funny you'd mention that in regards to self-insertion. For a while, when it first came to prominence, I didn't quite understand the hate towards NTR. I thought it'd be any man's fetish to be so much of an alpha, that you'd take someone else's girl, and corrupt her into cheating on her boyfriend with you. It was later on that it finally clicked on me: people self-insert as the MC, not the antagonist!
Maybe it's personal taste, maybe it's neurodivergence, but I always found myself cheering for the antagonist in movies, series, books. An automatic process, it's not me wanting to be different. Antagonists, to me, feel "cool", strong, like they don't exist in conformity with the protagonist's view, or that of the society in which the protagonist lives.
I transposed that automatically to NTR. My "self-insert" were the "antagonists". Curious how the same story can be read so differently by different people, isn't it?