An undergrad or not.
I don’t know who told you that schools don’t like to hang on to you. That’s ridiculous. Schools want to retain their students because they get to keep taking your money. Also, you’re probably going to be more inclined to stay in the graduate program since you are already familiar with the school and their system.
The same place for your resume what no other school would take you to stay in the same place for your undergraduate and doing so.
For your resume what no other school go there for grad school would take you.