As someone who has done both multiple times each, this statement comes off as someone who hasn't spent time in management. My stress levels are always much lower when I'm an IC. Even when I'm a high level IC. My blood pressure levels drop when I'm an IC. etc etc etc.
This is not to say that everything about being a manager is harder than being an IC. Not at all. But they're just not directly comparable the way you're doing here. They require completely different skillsets, and come with different challenges. For me, it turns out that the hard parts of manager life stress me out, big time. Thus I prefer IC work.