In my experience reliance on feature flags tends to turn any application into a mess of interwoven state. Feature flags are hardly ever removed and unintentionally creep more and more into the development future features as they depend on older features guarded by flags. If you use feature flags you must have a process of deprecating them to maintain sanity in the codebase.
Yes, this occurred at the initial stage of using feature flags. It's important to adhere to best practice guidelines and employ effective tools for their management. This includes implementing notifications for stale feature flags and conducting regular cleanups. Nowadays, some independent tools offer features for automatically cleaning up dead feature flags.