If I recall correctly, we only did this one year in grade-school English class. And it was indeed useless. Why would I say this? It was ultimately about putting something into a structural pattern rather than actually understanding the concept itself.
If a student learns the names of the parts of speech but really doesn’t get how to use them in practice, it’s as pointless as people who know that a discounted item at a store is a good deal but can’t figure out how much they will save.
In my opinion, the best way to learn is by using words and sentences in real-world situations.