If you have already tried UEFI, Device Manager, Surface Diagnostic Toolkit, driver reinstall, and updates, and the touchscreen does not respond even in UEFI, I would stop repeating software troubleshooting.
Microsoft specifically says that if touch does not work in UEFI, the touchscreen is most likely experiencing a hardware failure.
Your warranty being expired does not necessarily mean the Surface cannot be serviced. Microsoft currently offers out-of-warranty service for eligible Surface devices, potentially as a paid replacement/refurbished device, depending on model and country.