What industry standard? There's no industry standard for this stuff, it's just each OS doing what it wants.

As it stands System Settings now looks different from every other preference panel on the system. I helped ship a sidebar+search design in IINA and we do a far better job that System Settings does. Go take a peek if you'd like to see how this could've been done. (Personally, I think most apps should stick with top tabs, but we–and Apple–are constrained by how many preferences we can show on screen at once.)

There is no industry norm. KDE, for example, follows the approach described in the article. In fact even Windows has some control panels designed that way too (though Microsoft still cocked it up be creating multiple different settings applications each with overlapping utility yet somehow differing support for configurability thus leaving left to Google how to make even some of the simplest of changes).

I struggle to credit the idea that GNOME did something and that it's a standard; their whole thing ever since 3 is "innovation" (i.e. NIH).