They're a wide chasm between what one can make and what is led to making. React can lead to fast, responsive websites, though you'd be fighting against a current pulling you out to a bloated, buggy mess. There's a unique stench that comes from many react sites where everything is a skeleton screen, everything loads slowly, history rewriting is busted, there's no hotlinking, and scrolling is glitchy. Peek under the hood, it's almost always react. Facebook.com quality is the outlier, not the likely outcome.