I use CV when I have no idea. Then, based on the suggestions, I browse the taxonomy and try to find a reasonable ID, at a broad enough taxonomical rank.
I also use CV as a reminder, for species I have already observed, whose name I don’t remember.
I don’t use CV just to avoid typing a name I already know.
Because the auto-completion is very efficient.
Because I copy/paste the name in the photo file name before uploading, as described here:
https://forum.inaturalist.org/t/extract-species-name-from-photo-filename-upon-upload/6510/13