How to recover iCloud backups from two years ago that are now gone?

I made a one time backup of all my iPhones and iPads two years ago. I then turned off syncing on all devices so my storage didn’t fill up. This was a fail safe just in case one of my devices was lost or stolen. Yesterday, that happened and I discovered all my backups were gone.

[Re-Titled by Moderator]

Original Title: all my iCloud device backups are missing. I only realized this today since I lost one of my devices.