I think definitely an outdated curriculum, including too many mandates from the state on exactly what they should teach when and how. Teachers really have very little discretion. There’s also the bigger problem that the curriculum is too focused on content and not enough on real skill building, especially 21st-century skills like innovation, creativity, collaboration, entrepreneurship, project management etc.
I agree, an outdated curriculum is doing more damage to the educational system. This problem is compounded by the pressure of standardized testing, which often prevents resourceful and innovative teachers from stepping out of the clearly defined box of the curriculum. If there were less of a focus on standardized test results, I think teachers would have more freedom to explore with their students and feed their students’ sparks of interest in specific material.