On my website I have pages which date back to 1993-94. Still readable just fine. I used to post those links to mailing lists back then and they still get regular hits from people in that community because I've also maintained the URLs constant.
In my professional life though, I realised that 95% of the things I build will be changed in the next year or so. We often inherit projects that were only just finished, and our first task is to start changing it entirely.
So I aim for robustness of maintenance rather than robustness of the finished product. It's inevitable that it will change, but I can anticipate that in the same way a well engineered car can anticipate it's maintenance cycles.
My agency regularly take over older JavaScript projects - built in whatever JS-stack was trending at the moment. There are always big parts of the stack that are no longer available or in active development. Not to mention the enormous hassle it is to bring dependencies up to date for a JS-project that hasn't been updated in three years.
Depending on the circumstances we usually recommend moving it to a boring CMS like WordPress unless there are compelling reasons to double down on the JavaScript stack (if it really is more of a web application for example.)
As an industry, this is called job security. It is fascinating to be in an industry where systems requiring high levels of maintenance are preferred by the client.
Large entities have need and budget for their applications to evolve. The delta for websites is less intensive. For the latter, reliability and longevity is important.
[1]: https://developers.google.com/web/updates/2019/12/chrome-80-...
[2]: https://stackoverflow.com/questions/30876093/will-chrome-and...
Tell me that React websites today will still be around in 10 years time. With constant upkeep and maintenance, maybe. If a website is just a static website, not making it plain HTML is a disservice. The layers of abstraction will take its toll.