I mean, it's a a pretty realistic description of how some 'relationships' play out, both from the victims and the abusers POV. I do understand, that this probably isn't, what most people are looking for when reading or watching stuff.
Most of us do it, to escape from reality to somewhere, where everything is either fine/perfect or at least the villains always get what's coming to them in the end, when in reality it hardly ever tends to work out that way.
But the abuse starting gradually, with the abuser playing nice at first just to become worse and worse over time, and the fact that it isn't always (hardly ever) as simple as 'just leaving' to put an end to it, is pretty accurate to real life abuse cases.
You said pretty much everything I was going to reply. Many readers really act like character development means the character fights back or snaps out of manipulation, when it isn't that. Ut's slow, and many times abuse victims go back and ford. I even feel many readers have NO empathy for MC nor even care that he's not well in the head either because of all the pain inflicted on him. They want him to be the perfect victim that never gives up and HAS to fight back or else it's not character development
but this is really one the worst I've read !!! No plot, no characters development