For sure, there are many differences between plant based and dairy milk. Besides the protein levels, for example, a large percentage of humans - between 10 and 90 percent depending on genetic background - are lactose intolerant and can't digest animal milk. Plant based milks don't have this problem - very few people can't digest oats, and for those few who do have a problem with oats, they can switch to almond, rice, soy, cashew or even peanut milk. Sure, these have less protein than dairy milk, but they more than make up for it in diversity and benefit to the environment, and it's easy to adapt your diet to get the protein elsewhere.
So when being more honest in our comparisons - a good thing, for sure - we must compare all of these things and not just the amount of protein. For me personally, being one of those lactose intolerant people, plant based milks definitely win. For another person they may not.