Could be using CSS position: fixed
. But idk there could be other more sophisticated ways to accomplish the same thing.
In terms of why to not use it, I can think of reasons to avoid it by default. Like it could be very annoying on some devices in some situations. If the page authors made the table headings really long, it could obscure the content. I know I have been annoyed by this sort of thing when websites use position: fixed
for their navigation or other elements. When I’ve snooped around the backend of wikipedia I see that they are contending with a wide variety of contributors and users and whatever they do needs to accommodate everyone.
What I find surprising is that there is (apparently) no 3rd party browser extension, userstyle or userscript that allows enabling this.
must be