They have their use, but I'd say in most sentences the gender doesn't matter at all.

"She went to the grocery store.": Here the gender of that person is as important as any other attribute like the color of their shoes.

Imagine we have pronouns based on shoe color, let's say "de" for someone wearing white shoes. "De went to the grocery store."

And now someone proposes we could ged rid of that pronoun and you say "knowing what shoe color people wear is very useful though!"