They just stay in school.

Hi, I wonder if "they just stay in school" has a regular meaning in this context? to me it seems that the word "stay" means they didn't went up to another grade?

It's from this video link (1:04)

that is not bad, that means that it's not the size of your parents bank account, that decides whether or not you get an education, it's your hard work, it's your challenge it's your motivation. well you know what
happens, then nobody graduates from school, they just stay in school. of course people graduate according to a World Economic Forum on a list of the best educated populations