alt Hacker NewsI mean, prior to React the big Framework at the time was AngularJS 1 - a hellscape of two way data binding.
Talking about one-way data flows was an excellent way to speak to a lot of tortured souls at the time (who had just found out they were going to be forced to migrate their projects to something else anyway due to Google's absolutely insane "we're deprecating this, we'll have a replacement for it at... some point, good luck").
The first time my team uses AngularJS professionally, we spent a month to learn the framework, then the velocity and quality were good. The client reported a funny "bug" that the loading icon didn't show, it turned out the async request was too fast that they couldn't see to loading, a fresh experience for them at the time.