Every backlog I inherit tells the same story: good intentions, no curation. Hundreds of tickets, half of them duplicates, a quarter of them obsolete, and somewhere in the middle the things that actually matter.
I run the same audit on day one of every engagement. It takes about three hours and it's the highest-leverage thing I do in the first week.
Step one: age check. Anything older than six months that nobody has touched gets moved to an archive column. Not deleted, archived. If it was important, someone would have mentioned it in the last six months. If nobody screams when it disappears from the active board, it wasn't important. They never scream.
Step two: duplicate sweep. I sort by theme and read titles. You'd be surprised how often the same request exists three times, filed by three different people, with slightly different descriptions. Merge them into one ticket with the best description and link the requestors.
Step three: the "why" test. Every ticket in the top twenty gets this question: can someone explain in one sentence why this matters to a customer or the business? If the answer is "because [stakeholder] asked for it", that's not a why. That's a who. Push back until you get a real reason or move it down.
Step four: size reality check. Any ticket estimated at more than two weeks is not a ticket. It's a project. Break it down or admit it needs a proper brief before it goes near a sprint.
Step five: dependency map. I draw out which tickets are blocked by what. This always reveals the actual bottleneck, usually one team, one approval, or one technical decision that's holding up five things downstream. Fix that and the board starts moving.
After this, what you're left with is a backlog that's half the size, twice as clear, and actually represents what needs to happen next. The team can finally see the work instead of drowning in it.