You can't pick and use a library like this without understanding the underlying concepts. That goes for both encryption and the charset conversion issue. It's not always just plug and play.

There are examples of where people used encryption libraries in the wrong way and undermined the strength of the encryption (for example, CVE-2024-31497 in PuTTY).

A very big part of software development is dealing with leaky abstractions. We don't work with perfect black boxes. We need to understand enough of how things works in the lower layers to avoid problems. Note here that I wrote "enough", not "everything", or "write everything yourself".

I would not want a person writing software to handle charset conversion if he refuses to learn how the various encodings work, which charset will decode as another charset or not, etc.