No. And I'm surprised by all the other comments. There are some big systems still using CalDav but the promise of WebDav as read-write version of HTTP got very little adoption and the dev community stopped talking about it years ago.
It's unreliable; a tangle of half-implemented standards and incompatible clients, and it's uninteresting as a file system that lacks basic features, like locking, server-side search, etc...
Tried again recently, Windows 10 with latest apache webserver fails hard on simple tests.
Some technologies must just die and disappear.