If the labor quota is high enough… then nothing else will happen. GDP will rise, but individuals will steadily be sacrificing family, entertainment, and joy.
People will say they want to.
But they'll not make necessary sacrifices because it's outside their comfort zone
There are poor countries than Korea where survival is way more difficult, yet they've kids.
It's not about money or affordability, it never was.
Poor people in any culture have more kids.
Your comment is not based in reality and comes across as if "if I was millionaire I'd have kids".
That was also reflected in past Korean society where people frequently said the cost of one more kid is just "a spoon and a pair of chopsticks."
Very different from modern, industrialized Korea, where the lifetime cost of raising one kid equals multiple years of your salary. Unless you don't care about your kids and think they'll just sustain themselves by working in the rice paddy from age six to seventy.
That perceived cost is above the cost of living of a baby.
That cannot be fixed by simply offering them more money.
Okay, now you're just making stuff up.
Or they are simply overworked and don't have time to raise kids.
So, many "pro-birth" policies are aimed at helping women at work so that they don't have to sacrifice their career. But the government isn't doing much (our current president said people should be "allowed" to work 120 hours per week if they wanted to - and somehow still got elected), and what little policy Korea has is constantly attacked by conservative young men for being "sexist" because it's "feminist propaganda" that victimizes those poor young men.
And every year Korea slides further into population collapse.