The big takeaway here is interoperability. React is great, Angular was great for its time, etc, but if your company builds out all its UI components in a specific framework you're locked into that framework, so a lot of churn happens if you ever decide to try the newest hotness. It appears that all the major browser vendors are now in agreement on a Web Components spec so it's only a matter of time now before we have a good, standardized way of extending the web spec.