As far as I've read, and I am not a doctor (although am married to one), it's the lack of fiber and huge amounts of sugar and salt that contributes to most of the health issues we North Americans face. Meat-replacements though are more about environmental causes (as this article points out). I think they would do tremendously better if they could argue that they were healthier options too.
The milk-replacements are even worse in this regard. Oat milk seems healthier than cows milk somehow, until you realize it has 50% more sugar, twice the carbs, half the protein, and fewer nutrients. I really don't understand how alternative milks have positioned themselves as healthy and artificial meat somehow has not.
There are brands of Oat Milk that are better than others. I usually drink soy, but sometimes I want an oat milk latte and I find I have to ask the barista exactly what brand they’re using.
At home I just use Elmhurst plant milks, which function fine as a base. Then again, this brand works for me because I’ve never used milk as a nutrient source - it’s just a flavor or texture.
That's part of what makes it taste good.
And why it's just another processed food item.
The US diet is more salt centric, more sugar centric, more fat centric, than meat centric.