No, success in mathematics cannot be solely dependent on work ethic. You could work hard but if your basics are not solid then you are bound to struggle with problems that require higher-order thinking and assume basic knowledge.
Work ethic is one of the many factors need to succeed in mathematics. Some of the factors are:
- Structured thinking
- Identifying patterns and relationships
- Reilience and perseverance
- Understanding the utility value of mathematics
- Ability to apply learnt principles in other scenarios
This is not an exhaustive list but is a good starting point to think about success in mathematics.