Oat milk tastes pretty good because it tastes like milk.
Other than avoiding dairy, I’m not sure of the dietary benefit.
Almond milk is probably healthier.
do either have calcium?
no
I love oats and almonds, but grain-based and nut-based milk substitutes taste nothing like milk to me - not even remotely.
Then again, I’m not lactose intolerant. For those who are, I can well understand seeking some sort of substitute, and appreciating it for what it is.
Having said that, I think it’s confusing to call things milk that are not milk. Veggie burgers, oat milk, white chocolate, trans female… lies all lies!
I’d rather we leave the language as it is, and call things by what they are.