What is NOT an advantage of using OAuth for authentication?

Utilizing OAuth for authentication offers several significant advantages that align with modern application needs. The statement about its high level of complexity in implementation stands out as a characteristic that does not align with the advantages typically derived from using OAuth.

OAuth is designed to be simple and HTTP-based, which makes it accessible for developers and easily integrable with a variety of platforms and services. This simplicity drives widespread adoption, especially for mobile applications that require a seamless user experience. Additionally, OAuth enhances security by minimizing the necessity for users to handle passwords directly, which reduces the risk associated with password storage and management.

In summary, while OAuth does indeed require developers to understand its framework and flow, the complexity is often overshadowed by its benefits of improved security, ease of use, and compatibility with modern web and mobile applications. This makes the characterization of OAuth as having a high level of complexity in implementation an outlier when considering its advantages.