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Well, a data type isn't a function. As long as your function isn't unwrapping any data values (i.e. it's just shuffling them between functions/constructors), you can write it point free, but there's simply no syntax for point free matching. However, you only ever need one non-point-free function per data type: the fold. In Haskell, data types are pretty much defined by their folds. Taking the folds of the relevant data types as primitives, you can rewrite any function point free. Note that there are actually several possible "folds". For [a], the recursive one (which comes from the Church/Böhm-Berarducci encoding) is foldr :: (a -> b -> b) -> b -> [a] -> b. Another possible fold is the "case-but-it's-a-function" one, (a -> [a] -> b) -> b -> [a] -> b, which comes from the Scott encoding (recursion can then be recovered with fix, which is another "pointful pointfree primitive"), but, as @SilvioMayolo notes, there isn't such a function in the standard library. Either would do, but we don't have the latter predefined so let's just use foldr.

The fact is that Control.Monad is much older than Control.Applicative.

Monads were already in Haskell 98, while the paper about applicative functors was introduced in 2007. The package in Hackage exists since 2005.

Wikipedia:

Due to historical accident, applicative functors were not implemented as a superclass of Monad, but as a separate type class. It turned out that, in practice, there was very little demand for such a separation, so in 2014, it was proposed to make Applicative retroactively a superclass of Monad.

So liftM{N} are still valid.

You can’t do it without a little bit of boilerplate, but lens can generate that boilerplate for you, so that’s probably as close as you are going to get.

Using makePrisms from Control.Lens.TH will generate an Iso, which is, essentially, a first-class pattern-match on a single-constructor datatype. Conveniently, Isos are bidirectional, so you can view them (to get values out, like pattern-matching) and review them (to put a value back in, like using the constructor normally).

Using makePrisms and view, it’s possible to write getSeq in a pointfree way: