Silver back , while pure muscle, are tiny when compared to real apex predators like Grizzlys, Polar Bears and Siberian Tigers...
They have crazy strength— when compared to a human but outside of that and fangs have less tools than tigers and grizzly bears to harm something
Grizzly bears are faster, over 3-4 times the size of a silverback and have incredible strength on top of fangs and huge claws that would make quick work of a silverback gorilla in seconds
Also worth noting silverbacks arent apex predators. Theyre peaceful vegetarians unless disturbed.
For comparisons:
A silverback gorilla male can get up to 6 feet tall and 400 lbs
A grizzly bear can get up to 10 feet tall and 1700 lbs