I've personally never seen carousels out-perform alternatives like having multiple images on the page, or multiple landing pages with separate messaging, or just dropping multiple options for the one that's most important.
I'm sure that there are some cases where they're an effective option - but I've yet to come across one in testing.
As Brad Frost once observed "Carousels exist to keep people from beating the shit out of each other in meetings." - https://twitter.com/karenmcgrane/status/316563205294010370
And sometimes "people" is just the different people in your head who want to talk about ALL THE THINGS - when talking about just the most important one is what you really need to do.