In my experience it's usually 35-40 hours "butt in seat" time but 1 mins - 5 hours of work actually happen. The rest of the time is dopamine switching between news, personal communications, and other forms of non-work entertainment.

I count checking emails, work instant communications, and working through bureaucracy (paperwork flows) as work, not just hands on keyboard working on software solutions.

Also in my experience there are people who focus on only work at work, and they usually drag others into performing their job function.