I mean even if you are comfortable with grep, it is still not enough, plus then you have to reinvent all the rest of the functionality, ie an extension to automatically add references from a webpage, download pdfs and keep them in a directory with some local link to be able to find and open them, and then another tool to export a subset of the huge bibtex file for each specific project and sync them, as it would not make sense to share a huge bibtex file on every latex project where you need only a small subset.