Waterfall is a Boogeyman

“Waterfall” has always been a strawman punching-bag.  Every software project 

management approach has presented itself as an alternative to waterfall.  

Describing any approach as better than waterfall is meaningless.

The first formal description of the waterfall model is often cited as a 

1970 article by Winston W. Royce,[3][4] although Royce did not use the 

term waterfall in that article. Royce presented this model as an example 

of a flawed, non-working model; which is how the term is generally 

used in writing about software development—to describe a critical view 

of a commonly used software development practice.[5]

https://en.wikipedia.org/wiki/Waterfall_model#History