Why are academic textbooks a more reliable source than wikipedia

Explain why academic textbooks are usually considered a more reliable source than a website like Wikipedia.
Wikipedia is a website that anyone can post information on. This, therefore, means that the sources of the information being uploaded are not verified by academics or scholars. The information is therefore likely to be misleading, wrong and altogether unreliable. Academic textbooks, on the other hand, have been written by scholars who have the correct information and have their sources verified before writing any material. Information on the academic textbooks can, therefore, be relied on and it is not misleading.
Scholars and academicians who write academic textbooks are required to have carried out extensive research and which has been cleared by academic boards as verifiable. It is this research on the various issues under discussion in the textbook that the authors use to compile the final copy of the textbook. This is not usually the case in Wikipedia as the information posted cannot be verified to have been written based on conclusive and extensive research on the subject. Some of the information in Wikipedia can be found in individual blogs and hence purely based on opinion.