I totally agree to you on this cause overtime there's this local adage that says "All work and no play make jack a dull boy " this implies that no matter how busy or studious one can be there's time for fun and play which also adds up to the person wellbeing. So adding leisure as part of the things one can spend money on its fine by me, cause one still needs to allocate money for recreational activities that they derive joy from.
Relaxation of your mind is extremely important no matter what you do in general in your life, because your brain has to go through a lot of things, and they can disturb you mentally, especially stress, and to deal with that, you need to take occasional breaks from what you do for a living or to make money, and do something that you like doing, even if you have to spend money on it because it's important and it shouldn't be considered a waste of money which some people think of things people do for fun.
Some people gamble, some play sports, and even video games, and they might spend some money on it because they want to make sure they are enjoying the experience. If you love doing something that doesn't cost anything, that's even better, but there is no shame in spending some money on your hobbies or activities after dealing with so much in your life.
That's at least what I do, I spend money on my activities, because they help me relax and calm my mind to be able to deal with all the things once again. If I don't do it, I might give up at one point.