Google has close to the best internal tooling in the industry for a decade or so.
Then the Google engineers who joined Facebook missed it so much that they built a better replacement.
Replacement for what? Google has some good internal tools, mostly the older ones. They're lucky to be using React instead of Angular at Facebook though.
Angular was an acquisition and isn't all that commonly used within Google.
Closure was the homegrown framework that's everywhere. It is a different flavor of bad than Angular. Angular was basically "You too can make your Javascript look like HTML", Closure is "You too can make your Javascript look like Java", and nobody bothered to ask Why? For that matter, React was "You too can make your Javascript look like Ocaml." JQuery was the only framework that really let Javascript be Javascript (other than writing in vanilla JS, which post-ES2015 wasn't as insane as it sounds).
And then there's GWT which was "you can write webpages in Java." Yeah I never really kept up with the web frameworks there, just knew that for non-customer-facing things we were always recommended to use Angular, and that Wiz also exists.
Though to be more charitable closure was a direct reaction to the difficulty of maintaining a huge JavaScript codebase for Gmail and static typing like Java really helped. Typescript is better but closure was miles better than raw js.
Angular is not a developer tool, it's a UI framework. Closure might qualify, but it was not a general tool used by the entire company. The developer tools we're talking here are Critique, Blaze, Forge, Sigma, etc...
React? Lucky. I wrote Closure (with an S) at GOOG in anger 5 years ago, and only stopped because I switched teams.
It's more like Buck and Tupperware.
Sounds like a big-company issue, large scale lead to large burden and complexity.