There are different tasks, not everywhere the libraries could be applicable - because of different constraints, like, memory consumption, performance, etc. For

There are different tasks, not everywhere the libraries could be applicable - because of different constraints, like, memory consumption, performance, etc. For example, For many years I developed and maintained several libraries for high performance media type detection - libraries aren't applicable there. Similarly is for Dara extraction - sometimes you need to have tradeoffs between performance and other parameters, while libraries are optimized for average case.