The difference between an arrow and a sword is that it takes a couple real life hours to make an arrow so it doesn’t make sense to have it as separate components. Making a sword in real life takes several days to a couple weeks.
Compress a couple hours to game time and an arrow is made in 10-20 minutes.
Compress several days to a couple weeks into game time and you get 2-3 days.
As for what this is fixing or adding? Spending a day making a sword only to get interrupted long enough to forget what you were making or force you to make something else for survival and ruining your chances at resuming your progress, losing some of the equipment because of the interruption can further exacerbate the problem.
Lets take an example. The Machete. It takes 6 hours to make, multiply that by 6 and 36 hours is a mostly reasonable realistic time line for forging a basic blade like that.
Imagine instead of spending 6 hours, potentially starving, losing light, getting attacked, etc. And instead you spend 2 hours making a sword blank. Take a break, eat some food refill your focus, check your perimeter, etc. Then spend two hours to refine your blank, eat, refill focus, check your six, etc. Then you finish your blade with the final 2 hours. Its safer, easier to fit into a survivors schedule, etc.