What exactly do adult Asian kids mean when they say, “my parents won’t let me study X/pursue X career”? How do Asian parents exert control over their adult children in this situation?

I will preface this by saying that I’m not Asian myself.

When I visit online spaces dedicated to medical school/college/career plans, I have semi-frequently seen people say things like, “my parents won’t let me apply to study the subject I want”, or, “I want to be profession X but my parents want me to be profession Y”. Just recently, I saw a post from someone in the UK medical school forum saying, “my doctor parents are only allowing me to pursue my desired career path (non-medical) if I complete my medical degree first”. I never really understood what they meant about their “parents not allowing them” when they are over the age of 18, and whenever I probe about this, the answer is always “I have Asian parents/I’m from an Asian background”.

What I’m wondering is - what does “your parents not letting you” actually mean in practice for an adult Asian? Would they cut you off entirely? Is it about financial support? Is it about denying you an inheritance? The reason I ask is because, for most Westerners from a non-Asian background, your parents have absolutely no say in what you choose to study or pursue as a career, so if they tried to push you to do something you don’t want to do, you would just say “no”, and that would be the end of it. Why do Asian parents have more power in this situation than non-Asian parents?