You buy a second-hand but still quite new wireless gamepad. It dies unexpectedly at the approximate age of 16 months. There's a listing for a replacement battery on Amazon and a disassembly guide on iFixit, so you take a punt on a new battery and swap it in.
The gamepad's still dead, so you email its manufacturer for A) a repair, or B) spare parts, or C) to offer them even more money to fix it, but they don't provide any of those for a device still sold new today.