I listened to my dentist's advice to stop adding milk and sugar in my coffee. I now appreciate the taste of coffee much more, felt like reducing added sugar overall, and best of all I can be a coffee snob now. Win-win.
Milk isn't any healthier than any other drink. It's calcium content was considered it's primary benefit until a long term study was done that found we don't actually absorb calcium from milk that efficiently (like, 30-ish%). Calcium absorption in plants is much better, which makes sense since humans have been eating beans, nuts, and leafy greens far longer than dairy milk. We're built better for that. I'm sure populations have adapted more, somewhat, but there are still many places where the lactose intolerance is the norm and they're not all collapsing from brittle bones. The fat in milk is probably the healthiest part. You'd have to check the particular plant, but it even seems like plant-based milks might be better for all the health benefits than dairy. In general, low to moderate coffee consumption provides more health benefits than milk. You mostly just have to worry about caffeine levels.
I meant "healthier" like it somehow makes the coffee less acidic? It feels like that's what it's doing. Anyway, I hadn't really thought of it, but I meant oat milk above. I haven't had cow milk in years now. I kind of assumed everyone was going that way, but I have no evidence to back that up