Native CalDAV and CardDAV

At the moment I am using Thunderbird as email client because it can sync 2-ways with CalDAV and CardDAV. I do appreciate Thunderbird being free and opensource but somehow I find it "clunky" to use. I don't use plugins that could make it less "clunky" because I want to keep its installation as "pure" as possible to avoid issues when updating the app/plugins. I use Thunderbird for my small business.

So what I am interested to know is does anyone use any other email clients that natively work with CalDAV and CardDAV? Preferably free/open source but happy to pay if the paid one is better. I am most comfortable with Outlook but I need to install another app to make it sync with CalDAV and CardDAV.

Give eM Client a try; it's much like Outlook with much better 3rd party server compatibility. I don't know much about CalDAV and CardDAV, but it seems to have it.