Are reapers too one-dimensional?

I've been thinking about reapers in SC2 ladder and how they’re only really used in the first few minutes of a match before becoming completely irrelevant. This feels unique compared to most other units, which usually have some value at all or more stages of the game.

Is this a design issue, or is it just how they’re meant to work? If it is a problem, how do you think they could be made to be useful later on without breaking their early-game role?