1. Go to https://test.wikipedia.org/wiki/Main_Page?useskinversion=2
2. Run `OO.ui.Element.static.scrollIntoView( $('#Bureaucrats')[0] )`
3. Nothing happens
4. Go to https://test.wikipedia.org/wiki/Main_Page?useskinversion=1 and try the same thing
5. The "Bureaucrats" heading is scrolled into view, as expected
This happens because `<div class="mw-page-container">` has `overflow-y: auto`. This confuses `OO.ui.Element.static.getClosestScrollableContainer` into thinking that `mw-page-container`, rather than the body, is the element it needs to scroll. Disabling this rule in the style inspector fixes the issue.
I'm not sure if the right approach here is to remove the `overflow-y: auto` rule from `mw-page-container` (presumably it's there for a reason, but it's probably not intended to make that div a scrollable container), or to make `getClosestScrollableContainer` smarter and have it look at other signs of scrollability (e.g. `el.scrollHeight > el.clientHeight`)
See also {T255162} for the previous time scrollIntoView was broken.
# Update
The overflow-y also causes the issues described in T271868.