No framework is going to teach someone how to design a complex application that not only does everything it's supposed to, but does it well, and lends itself we

No framework is going to teach someone how to design a complex application that not only does everything it's supposed to, but does it well, and lends itself well to extension and modification over time by a constantly changing array of people. That takes years of experience, an excellent engineering culture and a well designed infrastructure. You can't expect React to do that. It's just a tool. React takes a developer from zero to one very quickly, but the rest is the craft.