If replies were enough, Staff Notes wouldn’t exist in the first place, right?
Whether to use replies or a dedicated feature is a UI/UX design choice. Simply replying means that misinformation and corrections appear with the same weight, making it harder for later readers to determine what is accurate.
Additionally, while staff-managed notes might work for small communities, in large communities, the workload for staff becomes overwhelming. This is why allowing trusted users to contribute to Community Notes is valuable.