It is way more of a hassle and so many buyers will go, "oh, I didn't know shipping would be that much, no thanks" after you put in the work.
That is one thing I don't like about depop. A huge percentage of people want something for nothing. I have shoes for 14.99 or less and they still try to offer less. Its always funny getting a message from one of them saying that they can't offer less on the app. LOL its because it isn't feasible dipshit!