“…In some languages, A-arguments are coded differentially when they are 1st or 2nd person (locuphoric), and this generally means that they lack an overt ergative marker, in contrast to other kinds of arguments, especially full nominals (Dixon 1994: 86).
This generalization about differential A marking is somewhat less robust than the differential object marking universal, but both belong to a much larger class of role–reference association universals (Haspelmath
2021), which all have the same explanation in terms of form–frequency correspondences, or more specifically in terms of the usual association of high-ranking roles (agent and recipient) with referentially prominent arguments (1st/2nd person, animate, definite, topical).…”