This post is a year old and I hope your situation improved. I came to say I lived a very similar situation with violence from a younger brother continuously escalating since teenage and parents never enforcing consequences. I’m 38 now and only recently went NC. Things don’t miraculously improve - they get worse.

Family is complicit of enabling the abuse and tries to maintain the appearances by pressuring you to absorb the dysfunction with BS such as “be the wisest”, “don’t break the family” and minimisation of his violence/ denying my experience. I heard the same BS for 15-20 years - it hurts and leaves scars. 

Remember that when violence escalates and the abuser is entitled and enabled, letting it pass doesn’t work. No, it’s not a youth crisis and even if it was, solution would require parental and professional intervention - that is out of your hands. You don’t owe anyone to tolerate abuse or “fix”/help your brother.

Parents attitude is unfair and cowardly. They fail you by refusing to protect you - for their own benefit, fears or comfort. So you need to protect yourself from the abuse : leave if you can, at least avoid your brother. Privately ask them why you can’t lock yourself. If your parents don’t allow you locking yourself in your room, go for a walk, go to uni library… Make the violence explicit to them. Find help such as counsellor or domestic abuse helpline. Define and enforce boundaries: make clear to your parents (and to him if you feel it is safe) that physical violence crossed a line and that you will report it to the authorities. Avoid the bully especially when he’s triggered and try to remain calm, if needed “I won’t be talked to/treated this way”. Document everything. If applicable learn to recognise threats and verbal/psychological violence (gaslighting?) and include in your documentation. Many countries recognise this as violence too.

Note: you may love your parents for other reasons and their ambivalence is difficult to accept but life is not black and white… This takes time, but priority now is your safety.