People who own/manage retail sales, are returns killing you too?

Since the pandemic retail returns have almost tripled for all retailers/business, now at almost $1T. The platform I sell on, eBay, has forced free returns for the auto parts category, which is what I do a lot of business in. This is what has been annoying me: 1. People don't seem to understand I do not have billions in capital like Walmart or Amazon to allow anyone to return anything for any reason. Even Amazon is cracking down on returns due to the increase cost/frequency of returns since the pandemic. 2. Rather than looking up or checking with me if an item will fit their vehicle, they just assume it will since I have to offer returns. 3 returns in 1.5 months simply due this this. Personal accountability has gone out the window. 3. I do get the option sometimes to deduct from their refund, especially if they sent it back used when it was sold as new, and anytime I do, they bitch and moan about how unfair I'm being. If I sold something and it did not end up working somehow, or arrive damaged, I'm not going to do that, but if you buy a brand new car part that you did not check to see if it would fit, and literally try to force it and then damage it, then that's on you. I've tried to explain to people I can't keep prices low and allow people to just return something all the time and the recuperation of funds has to come from somewhere, but they simply do not understand nor care. If all retail businesses doled out nearly $1T in refunds last year, where do you think that money is going to come from? YOU, in the form of higher prices.