I don't think people building websites explicitly think about the expected lifetime and plan for whatever specific lifetime they expect. On the contrary, peopl

I don't think people building websites explicitly think about the expected lifetime and plan for whatever specific lifetime they expect. On the contrary, people do that a lot. Every abstraction, every 'separation of concerns', every micro service or micro-frontend, is a response to the belief that at any moment a developer might need to replace some part of the whole. Pushing content into markdown files that can be loaded with any build process that understands markdown is an attempt to be build something where the website, eg the content, can outlast the current code. Every template-driven design populated by values from an API that's loading a dictionary from a database is decoupling the pages from the code, which greatly extends the life of the website. The website is not the code. That's just the part of it that you see. The website is the ideas, creativity, content, effort and understanding that went into defining what the code does. Some parts of the code might change relatively quickly, but that's the nature of code. We find better ways of doing things. Browsers change. We choose to optimize for different things. That's a good thing, even if it means throwing some old code away. It's a bit like the Ship of Thebes. Everything might have been replaced a few times, but the website is still the same website.