Fwiw, I've made >300k with a hard <40 hr week. Honestly, high salaries and flexible work hours seem like they should correlate (and always have for me): both are simply a result of how in-demand your labor is. There are certain jobs that require high availability, but many that don't, and if you're able to command a high salary, it shouldn't be very difficult to get some of your effective comp paid out in flexibility.