That's the catch - you don't improve as a sole developer. You can learn a lot, but actual improvement requires feedback. Feedback can also come from "oh, that

That's the catch - you don't improve as a sole developer. You can learn a lot, but actual improvement requires feedback. Feedback can also come from "oh, that doesn't work as well as I'd expected". Feedback from other people is usually faster and more efficient (so I agree with the recommendation), but isn't the only game in town.