How did support get so strong? Again?

I just watched a Challenger match where Blue had a Nami (enchanter support) supporting a Senna (marksman support) plus a Sona (enchanter support) top who had Spellthief (support item) even though it was a solo lane and she was getting half gold from CS, and Red had a Blitz support (tanky support) plus a Soraka (enchanter support) top. And guess which team won? The one with more support swag.

Now, keep in mind, any time a support thing is useful for anything but support, Riot slaps the shit out of it. Support champs get nerfs, updates, and reworks to keep them from doing anything but bot lane support (but it's fine for non-supports to support for some reason), and support items have gotten rework after tweak after rework in an attempt to make them something other than free gold. But here we are once again with support stuff everywhere. How does this keep happening? Is it the low gold reliance combined with a vision item? Why do solutions keep failing? We don't see more than one jungler per team - do gold gen and vision need to be tied to a special summoner spell like jungle has with Smite? Who knows? I sure don't. And neither does Riot.

P.S.: Saw a mid Pyke in a Challenger match a few days ago, so that rework didn't work either.