You are correct that the information velocity is too low. I think that's fine for thr kind of dabbling you mostly do in grade school though
On one hand, a lot of what I learned there was self-guided. On the other hand, the core concepts of programming, as it's practiced by the folks I know (mostly procedural, object, and functional concepts and knowing how to CRUD data) haven't changed that much even in the 40 years since I first wrote "Hello World" on a commodore 64. The tools have certainly changed, but the music is the same.
But then, maybe that isn't "the traditional classroom model" (though I think it probably could be) and additionally I may not be a "good" developer. :D
Actually doing the thing is important and given you can do that with Computer Science in schools discarding it because "you learn faster on your own" feels suboptimal.
Also while Internet access at home seems ubiquitous we don't have full coverage of high speed internet nationally so for some students being able to take a course could make all the difference.
Learn how to push a button A on a machine to start it, how to push button B to stop it. This can be learnt (and tested) perfectly. It is the ultimate in skills-based education.
Along the way, having worked on a few machines, a worker may piece together some information about 'starting' and 'stopping'. However, this is beyond what's needed.
Should schools be about skill based education? Or about that beyond what's needed? Beyond what's needed won't get the employer a greater short term fungible labour marginal return, why pay for it? Shareholder value!
Does it matter that no one learns Flutter? Teaching Turing [1] may be a step too far in taking programming away from real life. So it's a balance. But so so much more goes into learning computer science than programming language of the day that can be learned from Udemy. From O(n log n) to O(n), how a computer works under the bonnet, what a LLM is, to legal aspects, there's a lot more to computer science as a skill. The challenge of the education system is balancing sketchy employers and pitch-fork public, and the influence they have, that want a cheap quick fix vs actually empowering and inspiring high schoolers' futures.
[1] https://en.wikipedia.org/wiki/Turing_(programming_language)