because it makes them money.

animation has always ended up being a game of outsourcing it to cheaper labour.

U.S does it basically to all countries (be it directly or indirectly) back then U.S would outsource series like Batman the Animated series to studios like Sunrise in japan (which is directly related to why The Big O looks like batman). Modern times, its usually to korea (most of netflix' animated offerings. Avatar the last airbender for instance, has a lot of korean elements in the show.

Japan if not using home studios, will outsource non key frames to korea, phillipines, or vietnam.

this news is just saying a south korean conpany os outsourcing it to a north korean conpany.

Animation that has little to no merchandising basically always tries to make an animation as cheap as possible, because production of it makes little to no money. Unless you sit in positions like kids shows(which sell lucrative ad spots for toys), major merchandising animation giants (e.g disney, pokemon, gundam), a series is usually done at a loss to prop up some other sales.