hey, thats a very good question and one that we get very often.

Zapier is a complete automation suite where in an event will automatically trigger a bunch of actions without the ability to modify the event data or decide the action based on the event.

We enable all these usecases where a user will have to see the event and then chose which set of actions to trigger. the user can also send a modified version of the event data to the actions, while in Zapier, the event data consumed by the action layer cannot be updated in real time.