I think that this is bad idea and it increases non-working scripts(what if url stops working? ) . Also, it increases malwares.(what if url pointed to is changed

I think that this is bad idea and it increases non-working scripts(what if url stops working? ) . Also, it increases malwares.(what if url pointed to is changed to malware script?) Golang's package management is very good, but this isn't. Why can't they just paste the required script in main script itself? What's the necessity of import here?