Chatters / Viewers Helix API Endpoint
The existing API endpoint for getting chatters predates User IDs and only returns usernames. It's also part of TMI and not officially documented, which could result in it being removed at any point without any notice.
Many bots use the endpoint for channel loyalty points, and then have to make secondary calls to the get the user ID.
Not only for loyalty, this is very helpful for moderation, so you can see who is in the channel, especially which mods are online or not. The mods are also on the undocumented endpoint.
With the scheduled sunset of /NAMES the undocumented endpoint will probably be seeing and increase in usage. I'm sure lots of bot devs would like to see a long term/documented endpoint for chatter lists. Mostly related to loyalty points.
👍 This is still needed even with Twitch's Channel Points