Piper is significantly richer than the traditional world of pipes.
And herin lies the rub. The reason for the power and flexibility of pipes is that the pipe itself is very simple. All you do is connect the standard output of one program to the standard input of another. One doesn't have to build a description of the interface.
A pipeline is spontaneous and ad hoc.
Granted, that adapters are often employed by interjecting "filters" between elements of the pipe. These are generally awk or sed scripts, but are "first class" elements of the pipeline as well.