Now the question is what is 'work', and what is the company paying for? Knowledge work is tricky because it straddles the line between hours worked and knowledge applied.

A junior employee might work 10h/day to figure out a problem/get something working/etc... whereas a senior person may solve the same thing in 1h. This isn't the mythical 10x programmer, it's just experience and knowledge coming out when needed. The one with more knowledge also tends to accelerate their acquisition. One, because they can get the work done so quickly, they have time to keep expanding their knowledge. Two, they have all this groundwork knowledge which makes it easier to expand on.

So while it may look like your friend only 'works' for 1h/day, you could be missing all the time spent so that your friend could finish the work in only 1h.