A piece in The Conversation notes that Korea spends proportionally far more public money on early childhood education and care than the UK, yet its full-time maternal employment rate (56.2% in 2021) is well below the UK's (74.2%) and the OECD average (71.4%). If spending alone does not let parents combine care and work, what else has to change?

I agree with the view in the article you quoted. What matters more than the size of the funding is properly understanding the cause of the problem and directing it in the right direction. This is a problem with so many interlocking factors that finding the most efficient point of intervention seems to be the key. But I haven't followed research in this area for so long that I don't really know the current trends.