Ok, but, the average startup web dev stays at a company for like two years? And then the thing eventually gets rewritten anyway in the latest flavor of the week

Ok, but, the average startup web dev stays at a company for like two years? And then the thing eventually gets rewritten anyway in the latest flavor of the week, because nobody is using the same tools as two years ago. I guess the concern for longevity most devs have is amusing when most software, if its not like systems level stuff, or problems most devs dont want to solve, tends to get disposed pretty frequently. By the way, most of the software that actually sticks around was written in C and generally solves a problem most people wont tackle. Like zlib or sqlite or nginx or the linux kernel. You can almost pretty much judge the longevity of a piece of software based on how hard the problem it tackles is. Like encryption or compression? Those libraries are going to be around forever, because how many coders do you know that can write a semi compitent encryption library? And how manu coders can write a templating engine? Like most of web dev is throwaway code. It just is. Arguments based on like "will they be able to restyle it in 10 years?" Well are they even going to be around?