When I say “build anything”, I mean it works in nearly every environment, including natively in the browser. I can write the same code on the server as in the browser as in a mobile app as in a desktop app.

React has been around, and improving, for 12 years. You can run code from the first version today. The DOM has been stable since about 1998, so anything built on it should still run today.

It is true that JavaScript libraries tend to change quickly, but that doesn’t mean old versions stop working. It’s not like the native Linux ecosystem, where you need to build on the current kernel and libraries or it won’t work, it’s more like Docker or Flatpak, where you can build your libraries into your bundle and they will keep working. That’s why websites that were built 20 years ago, with the libraries of the time, still work today.