Being grateful doesn't mean accepting the current situation, but rather striving to achieve something better. That's not greed, it's more about wanting to change what's happening, and that's also a key aspect of gratitude.
I think everyone should be grateful, but we shouldn't give up. That's what makes us strive for better.
Giving up isn't an option for anyone, and it's certainly not part of being grateful. Because people who are grateful don't mean they've given up on their circumstances; they simply accept whatever situation they've been in after they've tried to do the best they can. We can identify ungrateful people by frequently blaming others or others without realizing they themselves often make mistakes, even quite fatal ones. Greed, on the other hand, is simply an aspect of human desire that seems normal at first glance. However, when greed becomes excessive, it can be very detrimental to that person.