There is no clear answer as to which material is better: fiberglass or carbon fiber. Both have their advantages and disadvantages that must be considered before a decision can be made.
For instance, carbon fiber is much stronger and lighter than fiberglass, but it is also more expensive.
Fiberglass is less expensive and still quite strong, but it is not as light as carbon fiber.
Ultimately, the decision of which material to use depends on the specific application and what properties are most important.
Generally speaking, carbon fiber is the better choice when weight and strength are the most important factors. Fiberglass is a better choice when the cost is a primary concern.