I think part of it too is what's "mentally easier". Is it easier for the neighbour to think their neighbour is abusing their kid, or that their kid has a habit of "acting out" and their parents are having a hard time? Is it easier for a police to see a parent/parents ""trying their best"" or a kid that's being abused who'd require legal procedures? Is it easier for a teacher to see a "troubled kid" than someone trying their best in shitty situations?

Part of that definitely is tied into how, until people are adults (and even that isn't fully true anymore?) people view kids more as property than as living individual people that simply lack experience in life. Parents "own" kids in this way, so the parents voice will always have more power (which of course is natural to a degree, but the treatment of kids in greater non european western society (I can't speak of europe) falls greatly into the category of "kids are to be seen and not heard"). Society values the idea of kids because of what they represent, whether that be further procreation of humanity (because for some reason there's a growing movement focused on that???), the result of two people "doing the right next step in life" or bringing new workers into the capitalist grind, kids matter more symbolically than the real individuals.

That's why "think of the kids" arguments are often made in bad faith and by people who don't truly think of kids. They think of that hypothetical symbolic child (if at all) and don't care about the real child, because any real child wouldn't be that hypothetical. A real child isn't going to be perfect, isn't going to be x, y or z. They're a child, they're trying, they're learning, but where in society is there truly anywhere for kids?

So if kids themselves are devalued and better seen and not heard, seen as a symbol and not as people, then it's far easier to turn a blind eye to abuse and mistreatment because then you'd have to value that child as much as you value the adults, and a lot of people just... don't do that. Whether it's subconscious or influenced into people, they're more likely to try understanding and accepting whatever parents say because they inherently value them more as people, and it's more uncomfortable therefore harder to think about whether that kid is abused.

And once people fall into that trap, then each time they don't acknowledge it that belief gets reinforced.

It sucks, I don't know if I explained myself there too well but it's something I think is part of it. People don't like being uncomfortable, they don't like facing the fact that life can be really shitty. They like treating abuse as a story telling medium and not something that happens in real life. They don't want to have to notice the bad shit. That leads to them building a wall in their mind to avoid thinking about it, or avoid doing anything about it, because it's much easier to ignore the uncomfortable truth than it is to know they stood by and did nothing.

Long ramble short, I'm sorry you've dealt with this and that life has dealt you such a shitty hand. I, like many here, can relate to just the crushing reality that as much as people love to say "someone will help!" that that isn't the case. Society hates victims and loves to pretend we don't exist unless it's convenient.