Hard disagree, I use the hover-to-preview-article feature all the time. Sometimes I just want to peek at a page to see what it is instead of opening it.
On Wikipedia's mobile view, collapsed sections are super useful (as the table of contents is not visible via the sidebar) and media viewer makes it possible to view details of an image/thumbnail without navigating away from the page.
> collapsed sections are super useful (as the table of contents is not visible via the sidebar)
Yes and no. On the hand some sort of table of contents is useful (but note that you could also just display it inline, the way it used to be done in previous desktop skins), on the other hand those collapsed sections break scroll position restoring when reloading the page after somebody (your browser or directly the OS) kicked it out of your RAM. This is because your (absolute) scroll position depends on which sections where expanded and which collapsed, and that information gets lost when the page reloads – all sections end up collapsed again and the scroll position your browser remembered no longer makes sense.
(There is some sort of feature that tries to restore the section state, but a) it only works within the current session, but not if the OS low memory killer kicked the whole browser out of your phone's RAM and b) even when it does work, it runs too late in relation to the browser attempting to restore the previous scroll position.)
So now that the mobile Wikipedia's full JavaScript no longer runs on e.g. older Firefoxes (e.g. one of the last pre-Webextension versions), the lack of a TOC is somewhat annoying, but other than that, somewhat ironically my browsing experience has become much, much better now that my browser can finally reliably restore my previous scroll position because now all sections are permanently expanded.
