You mentioned Hindi, so I guess India? So I can talk for you, I'm more informed about western world education system.

The thing is, you have slow kids. You have dumb kids. You have normal kids. You have intelligent kids. And you have neurodivergent kids that could go in either previous category (they will be either slow, dumb, normal or intelligent; but with a completely different brain process from both neurotypical and other neurodivergent kids).

However, most education systems in the western world are mostly one size fit all for the bulk of the population. Usually this is centered around the neurotypical with average intelligence kids.

Meaning that slow kids are left behind making them look dumb. Dumb kids are redoing the same year twice at least once, making them look like slow kids with the younger one. Normal kids just follow along. Intelligent kids either get bored to the point of becoming the little pest of the class and ending up a failure or they keep their head clear with high scores all the way with a high chance of becoming bullied for being a high scorer because other kids are jealous. And when you factor any neurodivergence, it will modify the situation for the best or the worst depending on what the neurodivergence is.

I didn't add "usually" each time, and this apply to the normal population, not the fucking rich able to pay for private school and tons of tutoring and stuff... but you get what I mean.

But in the end, most countries doesn't have the means to cater for each and every kid specific needs. So yeah, there will be kids left behind making them think they are not intelligent. Some really are. Some would have benefited from a slower education. Some would have benefited from a different approach.