Unfortunately I need to question the very premise of your post.
Consider the following scenario (suggests Socrates). Suppose that a teacher is asking a student questions. Suppose further that the student has access to a perfect Oracle. Suppose that the Oracle will correctly answer any question to which the answer is known.
Suppose for each question asked of the student, the student consults the Oracle. Since in most situations a teacher is unlikely to ask a question for which he or she doesn't already know the answer, the Oracle itself knows and gives that correct answer to the student. The student then transmits the answer back to the teacher.
What has been gained by anybody?
The teacher learned nothing new. The student has been nothing but a courier between the Oracle and the teacher. The student needs to learn nothing in this transaction and even if he/she tries to memorize everything all they wind up with is a disjoint set of "facts" rather than any skill.
Tasks are posed to students not to get answers or to create programs, but to elicit a change in the mental state of the student. We try to prepare students to answer questions to which no one knows the answer and to create programs that have never before been done. We do this by posing tasks that are in fact known to have answers/solutions but those answers and solutions are not known to the student. We want the student to treat the problem as if it is a really hard problem so that they will work through the difficulties - increasing their mental abilities through practice.
Suppose you spend a year or two never using your left arm in any way. Never even lift your hand or flex your muscles. What will happen? Of course, the muscles will atrophy. The same is true of your brain. If you don't use it you will find that it has turned to mush.
The answers you get on Stack Overflow (SO) are the answers of experts. They are like an Oracle. If someone knows how to do it, you may well find the answer on SO. But if you haven't worked on the problem yourself you are just a scribe or a courier of information.
You will never be able to solve hard problems unless you solve problems that seem hard to you. You will never be able to advance the art if you haven't practiced on things that require hard work.
Sometimes the "right" answer is the "wrong" answer.
I agree that SO has its uses, but anything that makes it seem like a panacea is problematic. It is useful to experts who need to produce something external to themselves and need to get past the hard bits efficiently. It can be harmful to students who need to produce a change in their own brains, which can only come from working through the hard bits. Efficiency is not a major goal of education. Efficiency will come, but it comes only from practice.
I don't believe that looking something up on wikipedia is the same as asking SO. Wikipedia probably has the answers you want (as does your textbook) but you have to work to figure out the details. It will give you background from which you can probably tweak an answer, rather than getting an answer directly.
A discussion group can work together to figure out answers to some questions. If the members are all novices this is not the same as consulting an Oracle and you learn different skills in any case.
More valuable than SO is asking your teacher to help get you over the hard bits. He or she can evaluate what it is you really need and either answer the question or send you off on a quest. So again, not the same as an Oracle.
A personal note (no, I'm not Socrates, though it seems like we were contemporaries). I became an expert in using Calculus by graphing literally hundreds of rational functions (quotients of polynomials) by using the information from the first two or three derivatives of the function. I did this completely manually, on paper. Today there is a web site that would do it for me and graphing calculators that will do it. I could do thousands of rational functions (instead of merely hundreds) but I would learn nothing at all. I would be just an observer. I would not have been able to predict the shape of such a function as I once could do pretty effectively. I might be an expert user of a particular web site, but that wouldn't have much effect on my brain.