Does anyone know why there’s no desire to see a working standard (protocol) for calendar/tasks?
It’s clear that CalDAV doesn’t function consistently across devices (and does seem to be dying as a standard). If you work across different devices/OS it’s virtually impossible to get things set up seamlessly. Companies and developers of task apps seem happy to create silos and not look at interoperability.
If you want to self-host, it’s too hard to do this and you really are limited to a tiny number of options.
What is your foss server set up?
(I do actually run an ok calDAV using Next Cloud. I’m suggesting that things should be much easier to use across different OSes and apps and devices).
Gentoo linux with Radicale on bare metal. Radicale is behind NGINX reverse proxy that slaps HTTPS and authelia redirect for authentication on top.
And of course i use DAV5X on android.