Oaks may fall when reeds stand the storm.
Those who are flexible and relatively insignificant can survive a crisis that brings down powerful who are unable or unwilling to adapt.
Example: In mass extinction events such as the one in which dinosaurs became extinct, large animals, which need plenty of food, go extinct first. Oaks may fall when reeds stand the storm.
Phrasal Verb:
let go of
release or free
Don’t let go of the rope until I’m safe.