As others have said this will vary from one student to the next. If you only consider academically excellent students, there will still be a wide range in terms of how much each of them is comfortable doing.
My main piece of advice is to not try to compete with other students, and do not try to guess what a top university is expecting. Instead, figure out what is right for you. Do you want to participate in so many activities? Do you need some time off to relax and “decompress”? In our family, what is right for one daughter is not the same as what is right for the other daughter. What is right for you might be different again.
Also I agree with other answers that academics comes first, or perhaps that your sanity and academics come first and second.