I wouldn't say that - Web Components (by themselves) do not allow you to write your view as a function of application state, which is the main draw of at least React.
But the initial use case of Web Components is to create a standard that allows developers to iterate on the web's built-in components (inputs, date pickers, etc.) without having to wait on the standards track, and FAST appears to intend to provide a number of such components.
(And there is more to such components than just styling (which is what Bootstrap provides) - it's behaviour, usability by people reliant on e.g. screen readers, an API to access its data, etc.