I would have said this a year ago without blinking an eye, but React is a little different.
There are a few things that make react different from stuff I've seen before about core react itself
1) Extremely fast release cycles with huge updates
2) Immense amounts of effort in backwards compatibility and codemod tools
3) Very cool and hard to do things being implemented in the core layer
For an example of 3, watch this talk: https://reactjs.org/blog/2018/03/01/sneak-peek-beyond-react-...
Dan Abramov does an amazing job at conveying some hard concepts beautifully.
