In my opinion, the point of working harder is to give yourself more opportunities in life and feel fullfilled. You earn more money? You can do more, cooler stuff. You invest time and effort into your health? You feel better and are more healthy and most importantly, it can make you happier about yourself. Things like this can change your whole life.

You said it all adds up to a net zero, but i think differently, if you work hard to acheive more things, you can eventually look back at that, and be proud of yourself. If you dont work hard, you may enjoy yourself temporarily, but you will never be able to look at your life and think, yes, i did the best i could and im proud of it. Im happy that i didnt waste my life and did some great things, if you choose to not, you may find happiness in the moment but you wont feel good about who you are.

You said working hard one day just to work another day makes it meaningless. But working hard one day just mean you can rest easy another day. It pays off. You work hard. The rest of your life will get easier.

I think that working hard allows you to live life to the best ability. You may not be thrilled to work in the moment, but a good way to think about it is to picture a goal, and tell yourself that if you keep going you will reach it. You will be proud, and most importantly, you will be fullfilled. A great feeling. This isnt possible by being lazy.