Do you have an actual question or are you just ranting? Also, Monobook was not removed due to copyright. It was removed due to a combination of issues. The two main issues were:
- Wikia uses a highly customized version of MediaWiki so they can't just hit an update button to get the latest stuff.
- The EU enacted GDPR which would have required significant changes to how the skin operated in the background.
Given the above two issues and that Monobook was not commonly used by that time, Wikia decided to just get rid of it rather than spend resources trying to update it.