This is not the definition of backward compatibility I have in mind. Backward compatibility also includes "continuity", that is the new features flow from previ

This is not the definition of backward compatibility I have in mind. Backward compatibility also includes "continuity", that is the new features flow from previous design. React has been redesigned 2 times and now with server components its even less of an extension of previous ways of doing things. Building 3 different frameworks where the old way to write code still works but nobody builds on top of that in any meaningfully useful way is a very minimal definition of "backward compatibility"