Earlier quoted context omitted.
If React is so great how come Amazon isn't using it in their store? I think last year an Amazon frontend engineer wrote some tweets explaining they tried React and it was too slow. So they keep using Java for SSR and sprinkle vanilla JS. They were still using jQuery until a couple of years ago and probably still are in some parts of their site.
React is in use in many heavily used frontends at Amazon, maybe not the retail site But there's no inherent reason React couldn't be used for a page that basically shows pictures of products with a description next to them, the bottlenecks will have nothing to do with the frontend in a well engineered system for that type of site
I'm discussing the retail site specifically because that's where CWV matter.
If a company has internal tools that take seconds to load it doesn't really matter. Captive users don't have much of a choice.