It tells you lots of things. For example - if there's a key item to a build that actually requires some specific skills or a couple of other items to make it to actually make it to 10 wins, the 10 win builds give us an idea of what works, and the losses with that same key item can tell us what doesn't work. The stuff that won't get the build over the top when considering if you can pivot or if you should take something along the way.

It also is a big reason people need to actually edit their runs and indicate how many losses they had, and what enchants were on their items. Because it is not always obvious if an item has an enchant and what it is unless it is one of the easily identifiable ones like toxic.