I'm an engineering manager and find it hard to relate to this. With 1:1s, ops reviews, planning, retros, design reviews, support syncs, etc., I have ~6-10 hours of meetings per day - then for non-meeting work I'm writing roadmaps, interviewing, managing escalations, doing project management, status reports, etc. How do you have 80% of your time free as a manager after this? I think that makes sense to code if you have that time, but my experience is that having that much time available as a manager would be an outlier.