Sigh...

Once again, you need to think more about the context.
Why the mother is doing nothing : fear. First she is probably scared that if she come in between, the dad will beat him more and herself. Survival instinct is something crazy and he probably threatened her that way. Also, how can she protect him more than shield that wouldn't work. It doesn't seems she is working, so if she takes him away, how will she able to raise him without money? Without a house ?
Same thing works for the uncle but in worst, first he is often in foreign countries, so not often présent. Second, even if he has money, he doesn't have the legal guard of him, he can't suddenly show up and take the kid away, not sure this is how justice works.

And finally : damnit, this is a story, it's a fiction, WE NEED THIS DRAMATIC STORY SO WE CAN UNDERSTAND HOW THE CHARACTERS WORKS. Seriously stop insulting characters that makes just sense in this story..if what we were witnessing was about real people, it would be different but rn, it's a story. What we ask you as a reader is to understand the story, their character and what kind of meaning the author want to give you all. I understand most of you reader as expressing their direct feelings but you also all need to take a few step back and look at the whole image, look at every characters pov.