The main benefit is memory usage. When you are working simple and you’re just working on one model it’s no big deal, but when you’re making a much more complex scene and your computer is screaming for resources, you have to use ways available wherever you can to save up on memory. Instancing is referencing an original mesh and it’s not doubling up and consuming memory, so you can instance the same mesh lots and lots of times and there’s barely a jump on memory usage, contrary to duplicating where is doubling up all the time and then before you realize, your computer is screaming. And then another good thing about instancing, you can make a change to the original and the change will propagate to each copy, instead of having to go one by one.
