Commercial milk just isn't that good a product. It's cooked at high temperatures. Things are taken out of it and other things put into it. The result is an ultra-processed product, and those are bad for you. Despite decades of recommending skim milk over whole milk, it turns out that whole milk is probably better.
Also people trust the foodstream less now because of some problems it has had. If people don't think the product is safe/healthy, they avoid it or at least buy less of it. Plant milks have an advantage because they haven't been around long enough to hit that many scandals.
That's one driver toward the rise of demand for raw milk. However, raw milk has one big disadvantage: you can't ship or store it. Do not even try. Almost all the problems with it are caused by people doing things they shouldn't. Keep the animals and the dairy spotless. Squeeze milk out of the udder and use it within a few hours. You're supposed to milk twice a day. One reason is the udder refills that fast. The other is raw milk won't keep. That's why we have things like yogurt, cheese, and soap to use up large quantities of milk. Pasteurized milk became popular because you can do filthy things with the cows and leave the milk in a carton for days or weeks. None of those are good ideas either, but people want very much to do them because it turns a profit and is more convenient than keeping a cow or buying/delivering milk every day. I wouldn't want to keep a cow, that's a fuckton of work. But I will happily buy minimally heated, unhomogenized milk when I can get it because it sooo much better. Seriously, the milk from local farmers is bright sunshine yellow in summer and pale creamy yellow in winter and tastes faintly of meadow.