I’m aware of the the suite including LibreOffice. It’s not popular with exactly the user base we’re concerned with here. Mostly because of aesthetic and integrations. If you dumped a hundred thousand dev hours into it, I’m sure it could find its way there. Otherwise, it’s still an excellent choice for who would otherwise be Linux users anyhow.
However, LibreOffice shouldn’t have to copy Microsoft. It would be ashame if it did too much.
This project, on the other hand, is precisely doing a clean room copy of Microsoft’s (et al) software. Not only does it go further as a drop-in replacement, but it’s also a form of protest in itself.