You can also engrave it with graphite on sheets of dry wood pulp
but use acid free paper, and store it someplace fireproof.
That is of course the reason for the seemingly crazy steel engraving.
If you want to store your seed phrase, you want to store it in such a way it won't naturally deteriorate, or be destroyed by fire/water in an emergency.
Many pens are organic inks which will decompose and lose visibility. Pencil is better for this.
Paper is of course subject to fire, water, and acid oxidation. you can get acid free paper, which won't yellow, and reject the ink/graphic. but fire/water still a concern.
galvanized Steel, stone, gold. these three materials can survive water, oxidation, and fire.
pencil/acid free paper in a fire proof safe. obviously one of the more simple solutions. I don't actually know how well tested the fireproofing on safe's actually is. water is still an concern potentially.
safety deposit box at the bank. bank vault I would expect to be pretty fire/water proof. tornado proof? Are they internally sabotage proof? if someone took lighter fluid into the vault, and intentionally lit a fire in there, what would happen?
sure at small values it sounds like overkill. but when we start talking about 100,200k, 1m+ you are going to want some assurances and backups. also, start splitting it up. 100k in one bank value, 100k in another.