javascript – What is the use case of BroadcastChannel API?

I’m reading about BroadcastChannel API https://developer.mozilla.org/en-US/docs/Web/API/BroadcastChannel . It seems that it is already on market for a long time, and quite cool as well. However, what still bugging me is any practical use case that we really need this BroadcastChannel. Appreciate if there is any real life use case.

I read a lot of tutorial and most of them using BroadcastChannel to solve authentication problem, which means that if user open 10 tabs of the same page, log out of 1 them will also log out all tabs.

However, I feel this can easily be done via cookies checking, or localStorage listener. Is there any other use case that more suitable for BroadcastChannel , or am I missing something here. Thanks