What is the point of a GPS approach if it offers the same minima as the conventional one?
Because it gives the aerodrome operator the opportunity to save the expense of maintaining out-of-date navaids. Every aerodrome I know of loses money hand over fist on provision of facilities for aircraft movements (and that includes the larger ones such as Gatwick and Hounslow Municipal) so anything that reduces that loss is welcome.
I think NDBs are due to go in a couple of years. Personally, I'll miss them but practically all the a/c I fly in now have GPS, even if it isn't a moving map. I always carry a hand-held and spare batteries, just in case.
TheOddOne