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Not sure if this is the same you're looking for, but Status Quo Is God is related.
I've seen this in Star Trek a lot. A new device arrives on the scene — a new computer promises to replace the Enterprise crew, a new machine promises to replace warp drive, a medical technology promises to extend life, etc. By the end of the episode, the new device is revealed to have a severe flaw that makes it unsuitable for use, so the old device isn't replaced after all.
Typically, they never mention the new device again, which is Forgotten Phlebotinum — instead of working to eliminate the problems in their new device, they just never mention it again throughout the franchise to reinforce the status quo.

In the Captain America: Brave New World, there's the talk behind the adamantium being even better than vibranium. The adamantium was never brought up in MCU before, what's the trope?
And also, what if such brand new thing/material just... Doesn't cut it? In one of the Disney Duckverse stories, I think the american/English one, that was selled as two-parter in magazines, the brand new metal was introduced from some small country in Europe, later showing it's not stable and is disegrating chains on ducks... And also Scrooge's big money house vault.
It doesn't even have to be a material, but just some thing, that is supposed to surpass the new one with the ending and events before showing that "if it ain't broke don't fix it" works into play.