It's quite easy and very cheap to make your own oat milk from oats and water, and a bit of fat if you want it creamier. This makes it a whole food rather than a highly processed one. Oat milk made this way is actually also a centuries-old, traditional food enjoyed by Northern Europeans for as long as they've been growing oats. Though it's far less nutritious than animal milk, it filled in when the sheep and goats weren't milking. For the extremely dairy allergic like myself, homemade oatmilk is the most cost effective, digestible, and environmentally sustainable alternative.