Newtypes have their uses, but as a replacement for named arguments they are an overkill in many cases. They solve different problems.

Newtypes are beneficial when some domain-specific value with an invariant is used extensively throughout the codebase. You would use them to store and pass around that value without fear that something goes wrong.

However if we start to create a type for each parameter of every function (which may not be related at all), it would only result in a lot of unnecessary boilerplate. Named arguments is a simple and elegant solution for calling a function in a more explicit way, nothing more.