If your kids really like something by the glass, that's really the only time I would use rice/oat milk or something if they like it. For baking, smoothies it just seems like a waste. If you think about it, rice milk/oat milk is just the nut, with some water, vanilla maybe, and sweetner. So if you are baking, just use water, with a little extra vanilla or something. For a smoothie, just add water, and extra fruit. If you likle the idea of oat milk, just put a spoon of oats/hot water in blender with a little sweetner and vanilla and blend a minute, and you could use that for the "milk" in baking. It seems expensive to me to spend a couple bucks on something that is pureed rice/oats.
I think almond and coconut milk is the healthiest. I don't always use a ton of canned coconut milk, so when i open the can, I pour it in to ice cube trays and use that as my ice when blending smoothies/shakes. It also makes THE best pudding/ice cream/custards!
The simplest ice cream is a can of coconut milk, a banana, 1/4 good cocoa powder, 1/2 sweetner, 2 tsp vanilla blend in blender until very smooth and freeze. DD actually likes this cold like cold pudding.