Different species have different life spans. I have seen rotundifolia that were a decade old: I counted the rosettes buried in successive layers of moss, like on a chain. Tuberous species are very long lived, and gigantea after a decade or so can get to be shrublike. I'm told you can stub your toe on the trunk. Pygmy species too can last years. The tropical species vary. Burmanii, sessilifolia and gladnduligera, brevifolia are pretty much annual species, but with good cultivation can go longer. Many are clonal: aliciae and adelae for example offset, and although the original rosettes may wane and die, the cluster continues. Many species die after flowering unless care is taken, and in nature this is not often the case. In cultivation, a good feeding regime after flowering with attention to humidity and temperature can revitify plants that are tired from flowering and seed set. Well grown plants usually reproduce quickly enough so that losses in habitat and cultivation are quickly replaced, whether from offsets, gemmae or seed. With gemmae, the resulting plants are identical genetically with the parent: one reason why the populations are self sterile. Since ithey are identical, it can be argued that it is all the original plant!