Springs do have a limited life but reality it for most of us that is not a problem. I keep a couple various mags loaded at all times, occasionally shifting them just because. Not to mention, one should rotate ammo on occasion, and that includes some practice.
Springs have improved in quality in the last several decades. I just changed the rear suspension springs on my 1977 project car, they were underload for over 33 years and had lost some height so it does happen.