Your desktop computer is very modular and almost everything can be upgraded yet still we get rid of it and buy new partly because not all new technology is compatible and the likelihood that other components are on their way out.
Modular construction goes way back and many products are built this way but there is a practical economic limit on the number of modules that can be replaced. The marketing of upgrade modules can never match original factory prices. We see how much replacement parts cost for almost everything now. What do you think a complete set of new modules would cost versus the original price? And you are still left with a worn case and perhaps obsolete style.