My point being that most issues with gear result from the ignorance of the user.
For instance, the OP's corrosion issue is well known. It's called "electrolysis".
Failing to prevent electrolysis is the users fault, not a fault of the gear.
Everything has it's strengths and weaknesses. Of course we must navigate them intelligently to get the most out of our gear.
Whenever we have more than one metal touching, liquid (even only occasional light condensation) and electrolytes (salts, acids, etc); then the conditions for electrolysis are present.
Since ferrocerium is made of at least six metals (
https://en.wikipedia.org/wiki/Ferrocerium),
that component is ever present with lighters, ferro rods, etc.
What we can do is minimize the exposure to moisture and electrolytes.
By the way, outdoorsman have had entire 4"x5/16" ferros turned into a pile of useless gray mess simply from a soy sauce packet breaking open between trips.
Thus ditching the lighter and relying on a ferro instead won't solve this issue. After all, lighter "flints" are merely tiny ferro rods.
On the other hand, I have soaked a Bic, a ferro and a chunk of fatwood in a bucket of water for three weeks.
Lit right up, no problem. Not many other ignition methods will do that for us!
The moral of the story is:
It pays to keep all of our ferrocerium protected from moisture. Especially during storage.