I'm not a vegan and I'm not lactose intolerant, but I'm 100% convinced that oat milk in coffee tastes much better than other options. It smoothes out the acidity and adds a mild nutty aroma. Almond milk and soy milk are good too, but oat is the best.
Cafe was out of cows milk one day, so i had oat milk instead. It was fine - it was different but I could get used to it. Prefer cow milk, but just because that's what im used to right now.