React is not a replacement for jQuery. I've seen many codebases that are written in React, but still include jQuery for some legacy function in the app that references $.param or similar. Using this stat to say anything other than "jQuery is bundled on X% of sites" is pointless.

If you could determine which sites are built using jQuery as the primary "framework", that would be informative. But even then, jQuery is just a library of utility functions, comparing it to React/Angular/Vue is pointless.

There's lies, damn lies, and statistics. Are those websites the professional applications that people tend to rely on and have the biggest impact (i.e. Twitter, Facebook, Gmail, etc) or are many of those personal or legacy websites and web apps that happen to be floating out there? Websites and web apps are a spectrum of complexity. The more complex a web app gets, the more painful the reliance on an imperative library like JQuery becomes. Despite all this, even many apps that are primarily architected in Vue or React or whatever may lean on JQuery as a dependency for legacy browser support or polyfills.