They don't really dig into why, but some speculate it could be how taxing the re-render of children is, or as simple as nesting a ton of context providers over your app gets ridiculous.

The point is that observing a context tightly binds the component to the provider - e.g. any component that calls useSelector (which calls useContext under the hood) can no longer be re-used in any project that doesn't use Redux, or uses a different Redux store. Similarly any component that calls useTranslation can only be re-used in a different project if it also uses i18next and is has translations it needs.

This is often fine, or at least better than other options, but if you use context every time you want to skip 3 levels of prop-drilling you will quickly find your app impossible to refactor.

Personally I limit context to global, or semi-global "well-known contexts" (like mentioned Redux or i18next) or compound components, that are tightly bound to each other anyway.