I believe Twitter uses React? Although it’s possible that Twitter successfully served you Twitter-Lite while FB may have mistakenly sent the full version.
React is ~6KB (even less g-zipped). React is very performant and its performance was one of it's original claims to fame over previous frontend frameworks like Angular.
Plus, it’s dishonest to look at react core size. react-dom, which is absolutely required, is 40KB minified AND compressed. Plus the usual plugins to handle icons, SVG, animations, and on on. A base React application easily crosses the 200KB gzipped mark.
React's performance (in large part because of it's virtual DOM) over Angular was a common benefit cited in it's rise to fame. Indeed no one ever claimed React was somehow faster than the document API (or even JQuery) and that isn't what I'm saying either. Whether or not you think the virtual DOM is wasteful in 2021 is a separate opinion and even Svelte devs admit the virtual DOM approach is usually fast enough.
> A base React application easily crosses the 200KB gzipped mark.
I didn't bootstrap a CRA app to check its full size, but considering a hero image alone can easily be larger than this, it still stands that React is certainly not "bloated".
It’s also established that byte per byte, JS is way more costly to download, parse and execute than images, the comparison itself is dumb.