Yes, it works well. I moved all my contacts and calendaring from Gmail to a self-hosted Nextcloud instance about two years ago. My wife and I have a calendars in common, both of which are set up as the default calendars on our mobile devices. We recently discussed having a shared address book too. Shouldn't be any trouble to set up. One of us will own it, farm out r/w access to the other, and we'll transfer contacts we ought to have in common piecemeal. CalDAV and CardDAV.

In general, Nextcloud has been transformative in allowing us to move off Google products. All our music and photos are on Nextcloud too.