First of all, every Swedish person I know seems to already have a higher standard of living than the American with an equivalent job in almost all aspects. Add to this the fact that the entirety of Sweden itself is maintained to a higher standard; consistently pure/clean water, well-maintained roads, clean parks, well-maintained public services, etc. I wonder how well the textbook definition of "standard of living" corresponds with real life. I think that einarvollset's point about actually having to spend time in Sweden to understand the quality of life is valid here.
Also, you're missing much of the point of the reasons that Swedish men choose not to initially take the leave. Your claim assumes that it's all economic, whereas the article cites that it is more likely a cultural aspect related to traditional thoughts about masculinity that discouraged them to take the leave. It's yet to be seen, but I'm pretty confident that if you gradually take away the bonus after 25 years, the numbers are likely to remain the same.