Security improvements tend to be a one way street, they are usually implemented in newer versions of operating systems, and by extension, on newer mobile devices. There is an assumption often made by technologists, that mobile device users are going through a constant upgrade cycle, but the assumption is made from a position of inequality, and grossly misunderstands how devices are used by a huge majority of the world. (Though in fairness, there is only so much support the technology sector...
