Those AOC tasks are training for skills most developers don't really need or train much (except maybe reading comprehension). Most code is quite boring, especially web dev stuff. Most of the interesting stuff is handled by external packages, you are just supposed to pipe it all together. It is still quite complicated work sometimes but in a very different way. It is only few developer that get to work on truly interesting stuff on their day job.
So the great thing is that AOC has something for everyone. A junior can take his programming skills to the next level, flexing some muscle he doesn't otherwise get to use. Advanced people can use it to either get to know a new language or take on code golfing and learn to abuse their favorite language in a new way.