Because the day to day job is nowhere near as stressful as the artificial constraints of the interview process. Do people typically come in to work at 11? Why

Because the day to day job is nowhere near as stressful as the artificial constraints of the interview process. Do people typically come in to work at 11? Why do you schedule interviews at 9 AM? Do people typically have time to think about problems on their own for a bit and start writing up a solution after they understand it? Why don't interviewees?