I agree. There are many practices common to countries reporting high levels of happiness that Americans (And certainly other western nations) ignore seemingly on principle.
We would have to analyze the actual distribution of that spend. When this is done, we see wealthier places have higher spending per capita because public schools in the US are funded primarily by property taxes.
One of the thing Americans do differently is setting up systems for inequality from the get go. First past the post voting, but also using education to produce/select 'winners', rather than use it as a tool for equality. One could say this is a choice and there's no wrong way to make it, but to me it seems clear that it is the root cause for many of the issues in the US. I think superstar systems and mentality necessarily produces inequality and inequality necessarily produces problems.