Public service announcement:
A crescendo is a gradual increase in volume. Ergo, when something ‘reaches a crescendo’ it has only reached a point where it is about to increase in volume.
If something has reached a high point in volume, it may be said to have reached a forte, or perhaps even a fortissimo. It has quite possibly completed a crescendo, but it has not reached a crescendo.
Please avoid using this phrase in the future.
Thank you for your attention.