Interesting question.
Well, I've tried both and the truth was that I liked the coffee with ice cream.
I am not a lover of liquor, and, for me, the combination of this drink with coffee is not good. That time I tried some artisan coffee with a liquor that was quite strong. I didn't like it at all (I had to give it to a friend so he could finish it).

On the other hand, coffee with ice cream is a delight, it is a combination of sweet and bitter flavors that melt in your mouth. My favorite is the combination of vanilla ice cream drowned by a strong espresso. It is very tasty, and as proof, I leave my tasting face 😁