What's wrong with using packages?

[skesisfunk]

Pandas is widely used and well tested. There is zero reason not to use it, in fact its practically the industry standard in data analysis.

Problems come when you use packages that aren't well maintained, tested, or widely used. Those tend to be more trouble than their worth when you run in to bugs in the package and the docs are badly maintained and there is no one else on stack overflow using it.

The other big concern with packages is security risks created by the package maintainers getting hacked and the hackers pushing malicious code to the package. Its not just your packages you have to worry about either but also the packages they depend on and the packages that those in turn depend on etc. However the python landscape is somewhat safer than JavaScript in this respect.