A question about the audtiton process and a pick for traniees

This is a question ive had for a while and maybe someone with more knowledge on survival shows can answer it.but im confused about the audtiton process genuinely they had said the had many global audtitons but its all korean contestants and Japanese contestants and one malayasian (not saying that isn’t enough) but I liked to ask are most of the trainees previous trainees? im suprised that most people didn’t get in from other countries this is not a hate post btw but I wonder if the global audtitons didnt show enough talent does anyone know the high standard they had for this program or was it out of complications?or are all of them trainees from wakeone and im overthinking it?or was it just the korean and Japanese audtitons were better?if you guys know or have a good guess can you tell me cause its been on the back of my mind .thank you