[pradn]

The use-case for having isolated objects with parameters, much like classes in Java, is to be able to a) share code, b) hide internal details, and c) have object behavior be governed solely by a constrained set of inputs.

So the point isn't to have your web component be different from the rest of the page. The point is that you can pass in parameters to make an off-the-shelf component look how you want. However, exactly how much freedom you want to give users is up to the component author. It is possible for there to be too little freedom, true.

See here [1] for a concrete example of someone writing a reusable web component, and figuring out how to let users customize the styling.

[1]: https://nolanlawson.com/2021/01/03/options-for-styling-web-c...