I’ve been doing web since 1990s and I‘ve always thought spreading a UI element across 3 separate files (often in different locations) was an anti-pattern (or 5+ files In 5 different folders if you want MVC).

React is awesome because it allows feature-aligned separation of concerns (each component has a single job - render everything about a specific element - which is usually a well defined part of a specific use case).

Jsx is the best UI system ever in terms of productivity - speaking from experience: I’ve implemented production apps using dozens of UI frameworks/platforms - Html, WYSIWYG, Flash, WindowsForms, WebForms, Ajax, Asp.Net Mvc, Razor, WPF, Xaml, Silverlight, Knockout, Handlebars, PhoneGap, Ionic, Bootstrap, MaterialUI, Angular2, React w/ Class Components, React w/ Mobx, React w/ Hooks

I can tell you pros/cons of each of those. But at the end of the day I can develop an entire app in days in React+Hooks which would take me weeks in most any other.