A system polling every minute is on average thirty seconds behind, and one polling every hour is thirty minutes behind - regardless of how fast the underlying signal is. When the consumer is an autonomous agent acting inside a request, that interval is the whole latency budget spent on waiting rather than on deciding.
A webhook inverts it. The change is delivered when it resolves, which means the freshness of your system is set by the source rather than by your own schedule - and the delivery leaves the edge closest to your endpoint rather than a single origin.