Bad ownership and bad luck would be my guess? They keep hiring bad GM's and bad coaches, they haven't "hit" on a pick outside of the first round since 2020 (2nd rounder RW with 103 points in 191 games) and there isn't much in their later rounds going further back honestly. Outside of Dahlin I'd say their first round picks have been middle of the road at best too, though I haven't watched Power much. I have no idea if their prospect pool is stacked but they haven't gotten much NHL production from their drafts in a while. At least the Wings have Seider and Raymond I guess, I would take them over the Sabres 1st rounders in the same timeframe.
I certainly wouldn't have hired Lindy Ruff as coach too.