Ask HN: Reliability of APIs vs Webhooks?

Currently choosing a 3rd party membership system to integrate with to check members with (Memberstack) and they offer webhooks and an API.

As I am always thinking in the worst case such as if an API fails to load or an important webhook is missed, I'm having a hard time choosing which approach to take based on reliability.

Extra curious if you were also in this situation to use one or the other.

Thanks.