Considering how many of todays highly effective knowledge workers where demoralized and demotivated in public school, you are talking about a short term effect. Personally I and many people at know greatly befitted from an easy public school education that enabled me plenty of free time to dive extremely deep into various personal projects. In comparison I took plenty of difficult electives in collage like Differential Equations for the fun of it, but thinking back I would have been better served with more free time.
I still remember coming up with the equivalent of the Bit Torrent algorithm in collage before BT was a thing, and thinking I just don’t have time to build it. In the wider context not a big deal, but don’t assume you can simply ramp things up without any cost.
And that’s a bad thing because? You where receiving exactly the kind of minimum education that was seemingly enough even if your grades where poor.
Remember life doesn’t hold your hand, self motivation is just as important for long term success as innate intelligence. Hand holding the academically gifted to cram as much as possible into young minds has been traded before it doesn’t actually seem to accomplish anything of note beyond excelling in artificial milestones like the Putnam.