Hypothetical::So the worst has happened, economic and societal collapse. My family escapes to a bitcoin-friendly (or unfriendly) jurisdiction. I do not have my hardware wallet. Before fleeing I smashed it to pieces, least it's confiscated. Seed phrase memorized and ready to go. Now what?
There is no instruction manual for event like this, but I would never count on my brain and memory to remember 12 or 24 seed words, I could always mix the order or make some other mistake, and if society collapses that would probably be a global event and not just local.
Having backup phrase hidden in multiple safe locations is much better option, and you can import it in any other hardware or software wallet that uses same seed phrase standard.
Problem is that society collapse would affect internet, communication, electricity and everything else, so your best bet is to wait for all systems to be restored.