Aligning the `=` signs of let/where bindings and function declarations is quite common, at least if they are one liners or, at least, only a few lines.

If they get longer, the individual equations are often separated by an empty line and are not being lined up anymore.

(Bored PhD students have even been known to write LaTeX style files to simplify all this in papers and their PhD thesis: https://github.com/mchakravarty/haskell.sty)