I was one of the implementers of the Apple Watch (OS 1.0) CalDAV support. We always wanted people to be able to "bring your own server".
You're welcome.
You're welcome.
CalDAV and CardDAV are wonderful cross-platform protocols that I use every day (including on Apple Watch) and I hope they continue to be supported in the future.
One day, hopefully!
I'm the author of this post, I assumed Apple still has support for these protocols because of legacy business systems.
I hope that the support for interoperable protocols continue to remain in future versions of Apple Operating Systems.