There was an article[0] on HN a couple of days ago about 'accelerated' education for gifted students, and how 'nonaccelerands' appears to have significantly worse outcomes. I suspect that students who are the best in their class can reliably put less effort for the same result as their peers, and then learn to 'coast' their way through life. Until they reach college-level, or the 'real world', where the workload often doesn't permit this.

[0] https://news.ycombinator.com/item?id=22901962