The best use case I know of for these kinds of things is as a way to prevent sql injection. SQL injection is a really annoying attack because the "obvious" way to insert dynamic data into your queries is exactly the wrong way. With a template string you can present a nice API for your sql library where you just pass it "a string" but it can decompose that string into query and arguments for proper parameterization itself without the caller having to think about it.
The best use case I know of for these kinds of things is as a way to prevent sql injection. SQL injection is a really annoying attack because the "obvious" way to insert dynamic data into your queries is exactly the wrong way. With a template string you can present a nice API for your sql library where you just pass it "a string" but it can decompose that string into query and arguments for proper parameterization itself without the caller having to think about it.