When a person is jealous, it means they are not able to reconcile with their own inferiority complex.
But understand two things: first, you are not necessarily inferior to the person you’re jealous of, and second the person you’re jealous of is not necessarily superior to you.
It’s your own perception that is deceiving you to direct hate towards the person. It’s a big waste because you’re wasting energy on a fruitless endeavour. You could turn that nasty hate into positive motivation (but it’s just so tough to do).
It’s much easier to find flaws in others, than to accept flaws in oneself. And that is the basis of jealousy.