Crab mentality
Someone exhibits "crab mentality" if they try to drag people down who are doing better than themselves. A form of "If I can't have it, neither should you" thinking.
Wikipedia says that "the metaphor is derived from a pattern of behavior noted in crabs when they are trapped in a bucket. While any one crab could easily escape, its efforts will be undermined by others, ensuring the group's collective demise."
For example, if one person from the family succeeds, the other siblings may become envious and try to undermine their success. A similar effect may occur in friend groups, if one friend gets a new job and starts earning twice as much as the other friends. Or on a societal level - some people don't want humanity to flourish because they themselves aren't where they want to be!