If you have a few developers in a room who have been working with React for 3+ years, there is a very small chance they will ask you questions like “the difference between props and state”.
Instead, people want to see your knowledge about common ReactJS patterns, well-known pitfalls, how to refactor and test your components and more.
You can work with React for years and actually have no opinion on some of the less practical questions and it’s fine. However, if you have an interview, then it’s quite important to have an opinion. Why? Well, first, it feels good to be able to answer interviewer’s questions and also shows your interest in the subject.