The note should cover the sentiment that XElement hopes to shrink and disappear over time. The library is not able to be described as a "polyfill" for anticipated w3c standards, but aspirationally it would eventually see functional areas replaced with browser-native solutions. This approach has already been working (see our adoption of CSS modules for example) (cite other examples???) but it does require making some predictions about the future that could turn out to be wrong.
Generally we want a small, idiomatic, un-opinionated library that sits between the browser and a "framework" like React