The solid-state energy devices that we interact with regularly are based on diodes. Examples include solid-state lighting based upon GaInN light-emitting diodes (LEDs) and solar cells based mostly upon silicon but also CdTe/CdS p-n junctions. Regarding upcoming developments, metal halide perovskite semiconductors have captured significant interest in the thin film optoelectronics community, but their longevity is not yet fully known. Our lab has been active in the understanding of halide perovskite degradation for nearly a decade. We have determined that metal halide perovskites not only feature mixed ionic-electronic motion but are also considerably chemically reactive, for example, via redox (electron transfer) or acid-base (proton transfer) reactions. So, one may ask, could they practically enter the commercial mainstream? After a brief introduction to these devices, I will attempt to answer this question.