Search trends and Stack Overflow tags are very dubious metrics for popularity of one framework over another. For example, one framework could require 3x as many Google searches as they other as developers try to grok the complexities of the framework. Angular is objectively more complex than React. This complexity comes at a cost.
React is above and beyond the most popular JS framework in existence. It is more than 3x more popular than Angular 2/4 and it’s growing at nearly 3x faster rate despite being 6 years old as a concept (Facebook started using React in production in 2011).
React has 69,527 stargazers on Github (https://github.com/facebook/react) to Angular’s 25,196 (https://github.com/angular/angular), making it the 4th most popular git repository of all time. React gains more than double the amount of followers compared with Angular every day: http://bestof.js.org/tags/framework/trending/this-month
React is downloaded nearly 270,000 times a day from npm (https://www.npmjs.com/package/react) compared with Angular’s 81,000 times a day (https://www.npmjs.com/package/@angular/core), indicating again that it has more than 3x the popularity.
React has had an extremely stable API over the last 4 years, changing little, especially in comparison to the ever-shifting Angular API story in that same time frame. If you learn React in 2017, you can actually look at React code from 2013 and understand it: https://web.archive.org/web/20131016111808/https://facebook.github.io/react/
Angular developers will have no such luxury. For all the “decision fatigue” you save in choosing a few libraries to pair with React to achieve the same functionality as an Angular app you lose flexibility, stability, and speed. React + React Router + Redux provides nearly everything you need to build a modern SPA application. Jest & other tools provide excellent testing support. For everything else, there’s NPM. React is simple to code, simple to test, simple to reason about, and scalable even at large enterprise teams. It is used in production by world class front end talent at Facebook, Microsoft, Apple, Twitter, AirBnB, Netflix, PayPal, HomeAway, Wal-Mart, NY Times, Spotify, Pandora, Coinbase, HomeAway, and thousands of others.
Facebook dogfoods React heavily. Google barely dogfoods Angular. Angular is but one of several front end frameworks/libraries at Google including GWT (Adwords and Wallet), Closure (which powers Google.com, Docs, and most of the web props you know and love), and SPF, (which powers YouTube). The Dart version of Angular is used for the parts of the Adwords backend dashboard. It’s an okay user experience I suppose, but it’s certainly no match for the results that companies have been achieving with React in production for years now.
When you begin with Angular 2/4 today, you’re 8 months into this framework’s maturity cycle. None of the old AngularJS directives are available to you. Many of the UI libraries available are not battle tested and remain quite buggy.