"为了入学而花费大量时间的很多EC,很多时候只能入学时有些用处,待到了职场上,几乎无用。"?
Wrong.
1. ECs are not just for 入学
2. If one can do multile ECs well, while still excels in academics, one stands out in talent/ability.
3. Hard skills are of course important on job, but soft skills (many are nurtured by the ECs) often are what actually determine how far a person can go