yeah, part of it is that. being a minor and less likely to fight against unfair contract policies and shady under the table dealings (which is why idols often sue their companies or act out at the latter half of their career.) plus the issue with military enlistment.
but also the same reason why professional ballet, ballroom, and ice skaters etc. are trained young.
being an idol requires several physical muscle/joint/stamina etc. intensive skills to handle their workload & it can't be developed at a later age.
still honestly kind of a shit reason & why i dislike both idol & sports institutions that treat older professionals as dispensable.
I think it because the more a younger child trains the more they become good at what they doing, children absorbs everything they being teach and those "absorption ability" slows down when you get older, same reason why athletes/professionals retire at a certain age despite being still young
Basically science tho on the moral standards it's definitely unacceptable to train and debut a child
honestly it makes no sense how the kpop industry doesnt debut older idols..also how is being in ur 20s old? personally i like em more mature & professional. it's said that in the showbiz they prefer younger people bc they'd be easy to manipulate & be dictated into doing things.