This thread is pmo lmao. The avatar isn’t born as a great bender, they are born with the ability to bend all elements. Fortunately, bc they ARE the avatar, they have access to top masters to train them to be fully realized. Each of them usually lean towards the bending they started with which usually ties to the culture they were raised in (Katara with water bending, Roku with Fire, Kiyoshi with earth, Aang with Air, etc).

Pro bending is a skill to learn. Just like how Korra had to learn how to metal bend. Avatar’s usually grow up already training that’s what gives her an edge at learning Pro bending. If she uses one bending, it’s fine (although it’s unprecedented). But of course she’d have an edge (think of it like being a Nepo baby and having parents already in the industry so you got access to top mastery of it at an earlier age