Why does everyone love getting straight A's?

I love my classmates and I love my teachers but it's getting ridiculously hard to keep up with my homework. I get about an hour and a half of free time at school a day, and I'm rushing non stop as it is. I know why I'm being pushed so hard, it's to keep up with the work level of AP classes. But I seriously wonder, how do my classmates manage to get all their homework done and find peace of mind about their grades. I'm getting good grades, but I'm constantly late on homework assignments, and I feel like the amount of work I'm doing is just way too much. I do extracurriculars as well. Everyone says that to get A's you have to work hard. But what about your mental health if you're working to the point where you can't get sleep?