Why Darknet Markets Use Multiple Onion Addresses
A single onion address is a single point of failure. If the node hosting it slows down, if a relay in your region has trouble reaching it, or if the address simply starts drawing unwanted attention, your only route into the market closes. Running several addresses at once is the cheapest insurance a market can buy.
Redundancy is the main reason
When a market publishes two or three mirrors, a problem with one does not lock everyone out. The other addresses keep resolving. For a buyer, that means the difference between a minor annoyance and being completely cut off from your store on the day you needed it most.
Rotation is the second reason
Onion addresses can be rotated to shake off accumulated attention. A market that changes its address periodically forces anyone tracking it to keep up. The mirrors make that rotation painless, because the new address goes live while the old ones still work, so nobody is stranded at the moment of the switch.
The practical takeaway is simple. Never treat one address as permanent. Bookmark the page that lists the current set, not a single link you copied from a forum post months ago.