[simongray]

This is the benefit. Languages like Clojure have excellent support for manipulating maps and I'd wager that something like 40-60% of Clojure code is similar-looking map manipulation stuff for this very reason.

If you need that validation, you just validate the map? You can use established methods like Malli or Clojure Spec for this. If you need to use a record with a fixed schema, just use a record instead of map. In Clojure, you can use most of the map functions for records too.