The auto parts stores pretty much don’t, at least in my experience, and push it off to the customers/borrowers. I’ve gotten broken or incomplete tools from the (free) lending programs enough that I’ve mostly stopped using them and just buy tools instead. I don’t have time to get stuck halfway through a job and any $50-100 tool still leaves me with cash savings overall on the job.

Even in cases where I told them I broke a piece in a kit, they didn’t seem to care and it looked like the kit was going right back into stock to me.

Parts store do it because it gets you in the door to buy parts. If the lending was done through the mail, I’m sure Amazon would sell more parts, but it’s not clear it would be enough more profit to cover 2-way (or 4-way if a tool was broken) shipping on the tools.