Million.js claims to make React 70% faster.

Why doesn’t React use a similar system (or Million.js itself) to render the DOM if it is so much faster?

As I’m writing right now React 19 is only available in beta testing. The main big feature that comes with React 19 is that it will now have is own compiler:

In order to optimize applications, React Compiler automatically
memoizes your code. You may be familiar today with memoization through
APIs such as useMemo, useCallback, and React.memo. With these APIs you
can tell React that certain parts of your application don’t need to
recompute if their inputs haven’t changed, reducing work on updates.

Does this means that Million.js will become obsolete with React 19?