I would argue that making it too detailed will cause more problems than it solves. It encourages you to focus and trust the estimates more however the model is

I would argue that making it too detailed will cause more problems than it solves. It encourages you to focus and trust the estimates more however the model is still far from reality. People may quit, people may get tired of working on something, they may realize they don't like working on something, some employees might be experts informally supporting other projects, some projects may not be as good for resumes or promotions, onboarding time is different for different people, some people really don't work well split across projects, etc.