What are the main disadvantages of the standard logger in Go?

Main disadvantages of the standard logger (log package):

• Lack of logging levels: The standard logger does not support message importance levels (INFO, WARNING, ERROR, DEBUG, etc.), which makes filtering and managing output difficult.
• Limited output format customization: Formatting capabilities are limited to predefined flags and prefixes. There is no support for custom formats or structured logging (e.g., in JSON).
• No support for multiple output sources: By default, output is only directed to standard output (os.Stderr or os.Stdout). There is no built-in way to easily configure output to multiple files, network sockets, etc.
• Weak context support: It is difficult to add contextual information (e.g., request ID, user ID) to each message without manual code duplication.
• Performance issues in high-load applications: Synchronous writing can become a bottleneck under intensive logging.
• No log file rotation: There is no built-in functionality for automatic log file rotation based on size or time.

These limitations often lead to the use of third-party libraries such as zap, logrus, or zerolog, which offer more extensive capabilities for structured, performant, and flexible logging.