The comments in here today are a bit out of touch.

>You can't do that with React.

You can. Other than React's rather hefty size, there's nothing stopping you. React is just a view layer, is unopinionated about how you get your data to it, and for rendering to a DOM needs nothing other than a DOM node to render into.

Try it out. You can have 100 different React components slowly eating your legacy app alive. You just gotta be smart about it.