how come there is no "appearance" button on the English wikipedia?
The "appearance" button seen on Dutch wikipedia is able to change the SIZE of the font (text) and the width of the article. This is extremely nice to have, but it's not there on any English article...
Technically these kinds of things are decided by the Wikimedia Foundation but they'll usually not do things that the editing community of the local wiki doesn't want.
In 2014 the WMF forced a new software feature (Media Viewer) on all wikis and enforced this by "superprotecting" the JavaScript on the German-language Wikipedia so local admins (who at one point even blocked the Deputy Director of the WMF from editing) couldn't disable the new media viewer. The WMF doesn't really want these kinds of constitutional crises to happen again.