Yeah, WD-40 depends too much on environmental and usage factors.
It's too volatile for long term rust protection. (And never use it for lubrication!).
I do use it for a lot of things, including flash rust prevention.
But only if I'm prepping for something better and I get delayed to the next day.
The other stuff is actually designed for rust inhibiting applications.
Boeshield and Crown 6007. Good stuff.
I've never used Flitz so can't comment there.