Don’t know why you would jump to that conclusion straight away. Mín billable hours and time spent thinking on the problem is a thing. Taking regular 5m breaks (pomodoro technique) also helps with getting things done and so on and people should be paid for it.
I mean, you should technically stop the clock if the wife calls to ask if there’s pasta at home but nobody really cares.
Adding significant amount of hours to a report would not be ethical but adjusting 10% to get paid for time laying in bed thinking about problems is still ethical from my point of view. It’s way more value than most meetings.
Your cultural context way vary.
Linux desktop and laptop