It looks like the rankings are based on an average of the K-12 and higher ed ranking. Because most of us are willing to move for college, I think K-12 is the more important ranking which goes to New Jersey.

Still surprising that Florida ranks #1 in higher ed. I wouldn't never guessed, but it looks like half of the metrics are concerned with economics of degrees attained there:

The higher education subcategory informs the best states for education rankings as well as the overall Best States rankings. It comprises metrics reflecting the share of citizens in each state holding college degrees, as well as college graduation rates, the cost of in-state tuition and fees, and the burden of debt that college graduates carry.