I have both, but use tarps 95% of the time in the backcountry.

When backpacking I love to be able to crawl into my sleeping bag
when it gets cold, and set my stove up just out from under the tarp. In very sunny treeless places, a tarp can be used for shade to read a book or take an afternoon nap. And I have a great view.
Tents get too hot.

I bring both car camping. I have a tarp for rain or shade when cooking and dining,a tent for privacy when sleeping.