For old PM the backlog is a memory prosthesis of all the old product conversations (a graveyard of broken dreams).
New PM will look at backlog in horror "what even is this I don't understand it", declare bankruptcy, "clear all that crap out".
Especially when all the tickets in the backlog just have 1-2 sentences and can't possibly be understood without the context that lives in the head of the original PM who wrote them.
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"Redo John's fix for frobulator service"
Definition of done: The fix is implemented correctly.
At one of my jobs, they used Asana when I started. It was too full of backlogged issues, so we moved over to Jira. Then Jira got too full. A month before I was laid off, one of my coworkers said, "Maybe we should try out Asana."