bvbfan In build repo Calligra is Qt6 based, but it could be pointed to master branch (https://invent.kde.org/office/calligra/-/commits/master/?ref_type=HEADS), it contains the Qt6 port including fixes and office suite could be usable again.
demm See the github commits for Calligra, it was again build from the latest commits a few days ago, still fails to build with spnav enabled, still fails on just about all plugins, so not ready to move out of build (it is not in kde-next). Example: https://github.com/KaOSx/apps/commit/fef0aecfb340ecf2fcf987f300d73cb9fd1be103 If you check the CI for Calligra, you can see they are not testing with any of the depends added for plugins or filters.
bvbfan Existing compiled application, in build repo, is unusable. You cannot open xls, xlsx, docx, odt, I don't see any reason to exist.
down8ve Calligra was an interesting project. It was positioned as a Linux version of Apple Pages, taking an alternate approach to word processing where all elements on the page were completely adjustable elements rather than being locked onto position line-by-line. Seemed like a great idea, but addressed too small of a market to really go anywhere.