Name at least one language that sounds like it is spoken quickly. Take Japanese or Italian. These languages, in fact, really are spoken more quickly than other languages. But do the Japanese and Italians convey more info in less time than someone speaking a slower-sounding language such as English? Linguists now say, “Nope!”
Linguists studying both speech rate and the effort needed to “get a message across” have found that exchanging one language for another doesn’t significantly change the amount of time it takes to get across any given idea.