It's true that writing your wallet phrase on a piece of metal or something similar will definitely be safe from termites and fire.
Not just from that. Also from water (paper, for instance, disintegrates when exposed to water) and ink fading (ink loses its color over time and becomes unreadable).
But the problem is how do we write our wallet phrase on it?
This has been discussed many times. The simplest and cheapest method is using stamps, where the text is impressed into the metal by striking a stamp made of a harder metal with a hammer. The resulting text is highly legible and sufficiently deep, and the process requires no calligraphy skills.
Because it certainly has to be engraved and that is clearly not easy, especially for people who have never engraved at all.
I suppose that learning to stamp legible text requires only a little practice.
Besides that, writing your wallet phrase on metal also has some small risks, but it can be big if not taken care of properly. Namely, metal can also rust, and when the rust is severe, it can make our wallet phrase invisible and that is clearly not good. So even though it is true that iron is fire, water, and termite resistant. But the weakness is in one thing, namely it can rust. So yes, this is just my personal opinion.
That is precisely why it is recommended to use corrosion-resistant metal (stainless steel, titanium).
Additionally, varnishes or paints can be used to protect the metal from contact with oxygen, which is the very cause of corrosion.
But what is clear is, wherever we store our wallet phrase, we must be careful. Because basically, caution is the most important thing. Because even if someone writes his wallet phrase on a piece of metal, if that person is not careful, he might forget where he put the metal.
Creating backups helps here - make several metal plates with the seed phrase rather than limiting yourself to just one. But if you can't remember where you stored these backups, which hold the key to your crypto assets, then it seems nothing can help you.
Draw a pirate-style treasure map with arrows pointing to where the metal plate is hidden.
