Bulk of the "transaction cost" in sharing-economy transactions is measured in time (registering, shopping, messaging, verifying, negotiating, meeting). In the case of renting/borrowing that's pretty much a fixed cost independent of the value of the item. So it ends up seeming more worth it for big purchases. I think that's why this type of thing is often seen on school campuses (students have a surplus of time and a lack of money), but not out in the rest of the world as much.

These guys are working in this space but they've switched from a borrow/lend model to more of a store: https://yerdle.com/