Very well explained. About log4j2, I think it came to exist because log4j fell far behind logback, and many veteran dev didn't like the inherent push for slf4j

Very well explained. About log4j2, I think it came to exist because log4j fell far behind logback, and many veteran dev didn't like the inherent push for slf4j over logback. While logback can be used standalone, snobs would yell at you. And since figuring out how to config slf4j over it can easily be less than half a day of work, many simply drooped in log4j2 and told snobs to go away. Note: In case someone is tempted to say that it is trivial to plug slf4j over logback, it is for greenfield work. Replacing an existing logging library, or the use of multiple logging libraries in favor of slf4j over one lib is a confusing matter, mostly because the error thrown at runtime are misleading.