The time to travel to the office is often ignored too (it sounds lazy to even mention it because it's the norm). If you're working remotely and it takes 30 mins to get to the office, you're at an absolute minimum burning 5 hours a week going back and fourth from the office when you could be doing something else. Add in the extra time changing to and from work clothes, and having to leave the office to get food instead of eating at home and the time adds up.

If you're freelance and bill by the hour as well then those hours easily add up to an extra day a week you could be working.