Automated webinar vs instant access to training

What are the benefits of using a platform like Zoom or Easy Webinar for an automated webinar funnel? Do you typically get more opt-ins if people have to pick a specific date/time to watch the webinar? Is there more of a commitment? Is this preferred to just opting-in and watching the training immediately? I know there’s no “right” answer here, I’m just wondering why evergreen webinars function the way they do.