This isn't so much about React as that the expectations for web applications have skyrocketed in the last five years. Before 2012 or so you could call yourself a front end developer with good knowledge of html and CSS and little bit of javascript. If you were working in the industry back then and you're one of those people, you've had to teach yourself to be a proper software engineer in that relatively small amount of time. It's possible that the complexity growth curve has rounded off and over the next five years things will settle down and mature (fingers crossed).
