tea urchin :
The driver is a software interface between your operating system and the hardware that allows (windows) to control your graphics card.
Your gpu was not discontinued, tho newer drivers may not be released.
Driver optimizations peak at the 18 months point_A newer driver would possibly increase performance in newer recently released games by a fraction,which is why updates have been stopped.
Actually, when I go onto the nVidia driver's download page and select my GPU and all the other pertinent info, they show me a lot of newer drivers for this card(GT630), but the newest that will actually work, no matter what OS, is the one I've been using since I got the GPU, which is from 2013(the driver, not the GPU which is even older), if I'm not mistaken.
Windows 10 for one, is constantly trying to update my GPU's drivers but I've blocked it through gpedit because I know the driver won't work because it's newer than the one I'm currently using.
That's why I suppose my GPU has been discontinued, because its newer drivers can be used by other, newer GPU's.