I think Millennials really are greedy and selfish.
Why do you have such a negative attitude toward Millennials?
The Millennials I've met were all about getting the most for themselves.
You shouldn't stereotype an entire group of people based on your interactions with a few. There's nothing wrong with people wanting the best for themselves.
People can't change just because you said so.
You should try to unlearn your stereotypes and think about the reasons behind your bias. It might help you to focus on your own goals and values and not worry about what others are doing.