> While I do have a fantastic memory, I don't feel like it makes a huge difference?

I'd say it does. Particulary for names based on English words with synonyms, if I recall the wrong synonym for this particular library, at least autocomplete is faster than searching the docs for all the synonyms. But not as fast as scanning the method/function list should the docs have that (and far too many miss it out).

If you can remember which word for the concept the method you're after uses, then you don't need autocomplete.

BTW only Jetbrains (and other heavy Java IDEs?) get autocomplete right IMO. The basic form in VSCode doesn't cut it in my experience, and gets in the way.