Did Flux really bring one way data flow? Because that's a pretty essential part of React. Even if React adopted it later, it's a core part of React's appeal.

Do you legitimately see no difference in websites from 2012 and 2020? I'm honestly baffled if that's true. Payments are a massive difference that I've noticed. Every decent ecommerce site these days uses quite a lot of slick tricks to make the purchase flow really easy. Whether it's autocomplete based on Google Maps address data or being able to do everything without any obvious page refreshes, payments are significantly slicker. React definitely facilitates this.

> There is no 'round trip' for server render

Uhh there is a round trip. You click on a link, the new page does a request, loads new HTML, new CSS and paints the new page. Sure, an SPA takes longer to load up front, but you can now ensure that everything past that point is seamless. On a site like Facebook where the initial load won't kill conversions (because people are already addicted), you can take a 500ms hit so that stuff like infinite scroll and seamless notifications keep people on the site.