In my 1989 G20 conversion van the electric pump in the fuel tank lasted 18 years, and then a good thunk with a mallet on the underside of the tank got me home but then no more, I replaced the pump,...
They simply don't last for ever. The best way to extend the life of any fuel pump is change the fuel filter when needed, it put's less stress on the pump.
Just like every thing elese its not built to last for ever.The most common case is they are liquid cooled and if you run or car on less then half a tank all the time the pump is being over heated.