What implementation are you using? Can you easily handle things like authentication and calendar sharing? For example sync a family calendar.
YMMV and a lot of people hate it, but I've run Nextcloud for this for years. It has pretty comprehensive support for WebDAV and CalDAV. Has sharing and lots of different authentication options; I use OIDC with PocketID.
It used to be a constant headache to keep running, but ever since I switched to the TrueNAS/Docker plugin it has worked smoothly. I know a lot of other people also have had good luck with the much lighter Radicale if CalDAV is your primary concern.
Radicale - https://github.com/Kozea/Radicale
I picked it because it's in a language I know (Python) and free and copyleft. These days I don't contribute to anything unless it's copyleft.
No idea if it supports family calendar, I need to look into that as well at some point.
EDIT Just checked and supports auth, yes.