I think it’s mostly a psychological thing. At some point in your kid life, you want to set yourself out from your peers(the pick me trend kind of stems from this) and your parents. You want to become independent, despite still being under the care of your parents. Due to this, you’re trying to figure out the boundary between independence while still being someone’s child. A lot of growing up is pushing boundaries and learning where it goes too after all.
So, when you’re trying to be independent but a parent is trying to take care of you, the two things conflict in a kid’s mind. And, without a way to fully articulate that feeling, a child usually acts out from embarrassment. Especially when they’re in public.
It’s a process of growing up, and by the time you’re an adult, you’re fully independent. You don’t feel that conflict anymore, since you understand you are already independent and just because your parents look after you, doesn’t mean that takes away from your independence. If anything, you start to miss the feeling of being taken care of and you recognize that your parents were just trying to show their love for you, not embarrass you.
Yeah, kids used to be like that. I don't know why we feel embarrassed/don't like about that? Growing up realises, there's nothing to be ashamed of feel bad treating them that way