It’s not only for the Lambda use case, my main motivation was AutoMods - they are very resource intensive currently and need to run very often. What you needed to do until this package, was traversing all new posts and all comments in there to check whether they’re newer than the last post / comment you’ve moderated. Which is a lot of api requests every minute or two, you’re essentially DDOSing yourself. With this, your AutoMod receives the information that a new comment was created and you can fetch the comment in a single (relatively inexpensive) api request, instead of plethora of requests which are all fairly expensive.
Whether the webhooks feature is then exposed to other users is really up to each instance admins, I’m thinking of exposing the functionality for my instance’s users when I finish implementing all I have envisioned.
Of course bot authors can add support for webhook triggering which means the admins can then use it more effectively.