Barbless hooks are one way anglers can help keep fish healthy to grow and reproduce. While there is some contention about the use of barbless hooks (which is now required in many places) it makes sense for anglers practicing catch and release. Less damage to the fish means more fish survive, grow, and reproduce. This means better fishing for everyone.
Barbless fishing hooks also have the advantage of allowing anglers to set the hook quicker than with traditional fishing hooks. This is because the barbless hook is able to penetrate quicker since there is not barb to get away. Although seemingly minor, this can be the crucial difference between whether you catch the fish or not.