Hours are not the constraint

Most people plan in hours and then cannot understand why eight hours produced two hours of work. The reason is that the scarce resource is not time. It is the number of hours in a day during which you can do something cognitively demanding, and for most people that is three to five, not eight.

Which reframes the problem entirely. The question is not how to find more hours. It is how to stop spending the good ones on things that never needed them — admin, messages, and the low-value work that expands to fill whatever it is given.