I don’t think the primary value in learning data structures and algorithms is the ability to implement them yourself. It’s more of a way to get repetitions in on basic programming skills while learning about the tools that are available to you. Later in a CS curriculum you might learn how to write an operating system or a compiler, not because you’re necessarily going to ever actually do it again but because it’s a way of learning how those systems work as well as getting repetitions building larger projects.