We consider what services must be maintained in order for our links into Medium to survive. We use Medium the company as an example for any other service offering persistence for creative works.
If I wrote something in Medium that you loved, how long could you save it without deterioration? What aspect is likely to deteriorate first?
Is the medium stable? Are the bytes of my work backed up by Medium? Are they in a code, say utf-8, that will continue to make sense?
Is the company stable? Does Medium or its successors continue as a viable business? Does preserving my work remain an obligation of that organization?
Is the work retrievable? Is it identified in a way that can be reliably retrieved over a network? Will dns, http, tcp/ip be maintained such that an identifier remains valid?
Is a copy ephemeral? Can you save a copy that survives closing a browser? Rebooting a computer? Replacing a computer?
Is the work memorable? What means will you have to find my work a day later? A lifetime later? Can your heirs find it? Your biographer?
A poem carved in stone can persist so long as the rigid medium is protected from forces stronger than those applied in carving. Longevity comes from rigidity.
A poem taught to children can persist through retellings and translations. It will survive so long as it competes successfully with other ideas propagated by a culture. Longevity comes from replicability.
A work in Medium depends on technology with a lifetime measured in decades sustained by an organization measured in quarters. It appears more rigid than replicable but is really neither.
Centralization enables innovation but interferes with durability. See Life with Transistors