My primary use case is to get a list of banned users for easy display/management, the POST endpoint would be to help support automod features, especially around being able to track what mod did something, and not needing to be directly in chat to be able to manage timeouts/bans in chat. Another use case would be cross client integrations, such as minecraft servers, curse voice, discord, teamspeak, etc. If you ban someone from those servers, you can create a plugin that auto posts to the twitch endpoint (if you have twitch account linking) to ban/timeout that user from chat (or unban them)
The single user unauthorized endpoint is primarily for channel transparency on what’s going on with timeouts/bans, especially for fast flowing chats (think kripp speed) where the ‘you are not allowed to talk for some # of seconds’ just vanishes in the blink of an eye.
Single user authorized is to support research efforts for (mostly) moderators, so there’s an easy way to tell if the user is actually banned, and if so, why. (Add the json response result to an app that can track bans and you have a comprehensive dashboard for mods to research if a ban is justified or not)
The full list would make retrieving the full list of bans for auto unbans after time easier, or unbans for type offenses, basically, a pardoning system for non violent offenders.