school: essential for learning the basics, but is hugely bloated with unnecessary things to learn, that, despite being mandatory, only have niche uses for niche fields — even the existing "basics" are often filled with extra content that isn't needed; additionally, the education system is flawed in every country in one way or another, even if excluding the aforementioned overfill of many useless things we have to learn
wikipedia: while not perfect, it is still suitable for more "casual" information gathering (i.e. just browsing at home), especially if one cannot find more detailed sources due to a lack of time or other reason; of course, for more "professional" information gathering, the specific pages and sources catering to the desired subject/topic/context will almost always be a better option than just quickly reading through the wikipedia article(s) on it/them