Why do you think so? I don't even remember the last time that I used lazyness myself. Not to mention that there are other pure functional languages (such as Idris) that are strict.
You can consult Okasaki's thesis (regrettably it is somewhat out of date) for a list of functional data structures. Some of them are lazy, some of them are strict. But being able to use all them is essential to getting good asymptotic complexity.