Most people's setup is probably this: single sig, seed phrase on steel plates (which relies on the physical security of the plates) and a passphrase (on steel or memorized).
Let's say you have a relatively small stack with that kind of setup and you're moving abroad indefinitely.
If you take the plates with you on the plane in a carry-on bag or in your pocket, they may get seized or airport security may take photos of them. Checked luggage is even worse, because you wouldn't even know.
Memorizing anything is only as good as your memory. A passphrase may be easy to memorize (you can use strings that only mean something to you while still maintaining a good amount of entropy), but seed phrases are much harder.
Steganography may be a better option.
If you're not taking the plates with you, you want to destroy them. How would you go about that?
If the route you're taking compromises the original seed phrase, you want to generate a new seed phrase upon arrival at your destination and move your stack to the new wallet with a new passphrase. Even if your seed phrase gets stolen en route, it would take the thief some time to brute force your passphrase, hopefully longer than the duration of your journey, so you can move your stack before they manage to siphon it off.
You could also move your stack temporarily to multi-sig and move each seed phrase using a different channel (e.g. carry one with you on a plate, xor another with a passage from a book then GPG-encrypt it and send it digitally etc.)
What would be the most practical way?