It is not just to have it in the bank. It is so that it is in the bank to enable buying one or several properties at a huge discount instead or sitting on the sidelines while other people buy them up.
This is a good point. It’s not like someone would borrow money at 6% and stash it in savings at 3% indefinitely. They should obviously have an exit strategy or a planned use of those funds in the future that will pay off.