Yeah, you'll enjoy life more if you're not working 100 hours a week like Elon Musk. But I think you'll be in general better off and happier if you push yourself.
I've always worked very hard at my career and it has paid off. I get to do lots of fun things as a result. It was hard in the moment to make the sacrifices, but that's water under the bridge now. Present and future me are very happy past me spent so much effort getting better.