Feature-flag lifecycle management: when do you actually delete dead code vs. keeping flags for analytics?

We've accumulated 47 active feature flags across two services. About 12 of them have been 'on' for 6+ months with no plan to toggle off. The team is split: 1. Remove the flags and clean up the branching logic immediately — reduces cognitive load and test matrix. 2. Keep them because the analytics dashboards reference the flag events, and marketing wants year-over-year adoption data. How do your teams handle this tension? Do you have a formal flag retirement policy, or does it decay organically? Curious about tooling (LaunchDarkly, Unleash, or homegrown) and whether you separate analytics flags from deployment flags.