Bullshit fake work is way worse than strictly time-boxing work. A focused 20-40h/wk is a lot more effective than 100h/wk of working on 90% bullshit, particularly because the bullshit reduces your per-hour marginal productivity as much if not more than real work, so you're not even getting just 10h of real work. And because 90h of bullshit this week means, due to sunk cost fallacy, prior commitments, etc., you're basically going to have to spend at least 50h the next week on similar bullshit.