Most web apps/websites aren't a whole lot more sophisticated than they were in the days of Netscape Navigator 3.0. They show text and pictures, accept form submissions and resize the viewport when I change the window size. Yet today they seem to require multi gigahertz CPUs to do anything acceptably fast. Yes there are a few that were not possible back then. Most though can't justify their resource consumption. Neither on the client nor on the server side.