It shows the majority of its strength in switch statements. You can mostly just use the instanceof for a one line destructuring of a compound object into its constituents. The corresponding rust statement is the `if let` or `if case let` if you are more of a swift fan. Generally you would use it with sum types which were previously extremely nasty to work with in Java but are more useful now with sealed classes.

The pattern shows up a lot with result and option types but you can do it any other time where a tagged union makes sense. The classic way to do a tagged union in Java was just a personal taste amongst bad options: tagging interface and instanceof on implementations or an encapsulating class that will return null (or throw an exception) if the gets are called for the types which aren't encapsulated.

If in your career you never needed to enumerate cases that required different data in each case and you couldn't see how binding those requirements into an invariant via the type system was helpful then you probably won't use these new features either. Some people thought it was helpful but the boilerplate cost was too high so wouldn't do it in practice (I am in this category).

Edit: you could also make tagged unions more type safe with callbacks, but then implementing a closure to pull the value out of the callback was just annoying.