I've written a book on both Angular 2+ and a book on React. I've talked w/ hundreds of developers on both sides and I can tell you that people with different constraints (and backgrounds) will have a different response.
The author of this article cites "more ReactJS libraries on npm" to imply that React is the better choice. Some people love a la carte infrastructure and the power that comes from choosing each element in your stack.
Some people love to have those decisions made for them, because they just want to build their app.
It's often cited that React is "simpler" than Angular, and if you look at just the core that's true. But by the time you pick a data architecture, styling choice, router, etc. you're back at the same level of complexity.
Actually in React, you've spent a lot of time researching which components you want (and if they'll even fit together). The pro here is that you get just the stack you want! The competitive evolution of these libraries means that you _can_ have 4 routers and pick the best. But also, if you'd just picked Angular, you just use their router and move on.
Here's another litmus test: Do you want 'string' templates or JSX? (Now, I know it's technically possible to do either in both frameworks, but it's almost never done in practice.)
Almost everything that seems "more complex" in Angular is a result of string-based templates. DI, AOT, the *ngIf and `let` syntax, is all because you're doing templates in strings instead of code. How do you feel about that? Would you rather write templates in JavaScript/JSX? Then use React. Do you have designers doing HTML on your team? Then use Angular.
(Also the other opens by citing webpack, npm, and third-party libraries as a React-specific benefit, but that makes no sense because angular-cli uses Webpack, it's on npm, etc.)