You want me to have how many services running just so I can have a calDav/cardDav server? And sometimes you'll just stop working because of some unrelated issue of something I'm not using? Headache upon headache when you depend on it, but only for one thing.
Radicale people. Forgive me for doubting you. I have never used Radicale but I certainly do now just to point people away from nextCloud if all they want is a calDav/cardDav server.
Who knows, maybe in a few months or years I'll just throw in the towel and install Radicale and FileBrowser and just rely on `rsync` or Syncthing for the desktop/mobile sync.
They all use open standards (CardDav, CalDav, WebDav), and that's why I can use DavX5 on Android and Gnome on Linux and Apple's default accounts/apps too.
bewCloud has and will have a simple UI for each of those just because I think there's value to having an easy web access that's not sync-dependent.
I hope that makes sense!
Meanwhile, if you approach each module as it's own project, but with shared code where sensible, and open standards driving your integrations, people including you, can select the parts that best suit them while mixing in software from others where appropriate.