Chris De Jabet, writing on the 1Password blog:
We learned from customer feedback that some people would make a vault named Archive and move these items there, and others were storing those items in the Trash. While both solutions work, neither was ideal. That’s why we’re rolling out the new Archive feature in our latest updates.
For the longest time, I’ve had an ‘Archive’ vault in 1Password to hold old items that I no longer used, but still wanted to store in 1Password to reference. Items such as old server passwords, accounts from sites that are now dead or moved, random secure notes, etc. were all moved to this ‘Archive’ vault. I can finally delete that vault now that 1Password has native support for the Archive.