Wikipedia is rough amalgamation of several kinds of specialist encyclopedias
Wikipedia is, in many ways, the amalgamation of several kinds of specialist encyclopedias, in addition to being a generalist encyclopedia.
Taken separately its thousands of articles on specific airplanes amount to a reference work on the different airplanes, present and past, which would usually appear in a unique reference works in the reference sections of libraries. The same thing can be said for its thousands of articles on plants. Finally, the same thing can be said for its hundreds of articles surrounding Pokemon.
Several decades ago in the age before the Web the Encyclopedia Britannica tried to address the issues around the split between a "generalist" ready-reference encyclopedia and a more specialized encyclopedia giving deeper knowledge of certain topics, by splitting the encyclopedia in two, between Macropedia and Micropedia. They were limited by the realities of paper publishing and could not cover every topic in depth in the macropedia, to correspond or expand on the short view in the micropedia. Wikipedia does this, in several topics, with several different degrees of achievement.
Because the number of Web-savvy airplane fans out there greatly outnumber the number of Web-savvy antique fans out there you are much more likely to find a good (albeit incomplete since there is no mention that it was the first allied aircraft to bomb Berlin in WW II) article on the Farman F.222 than on the Escritoire.