Well, they grow into happy cows because I don't like how veal tastes.

Less snarky answer, I will concede that milk production comes from repeated breeding and is intentionally exacerbated by removal of the calf. And also that we could just....not do that. However, I would like to correct this and say that dairy cow is a breed.

Beef cows are bred to be stocky for the meat. Wagyu beef, made famous and expensive for its texture and marbling, cover only four breeds of cow. You're not getting wagyu from a dairy cow.

Regular breeding cows produce around 1.3 gallons (5 liters) of milk and gradually dry out over the course of a year as their calf grows and stops drinking. Dairy cows have the same time constraints, but produce eight gallons (30 liters).

They've been altered intentionally to far overproduce as a breed and while tapering off would be possible, they would need to be monitored every time they're lactating so they don't in significant pain or die somehow.

It would be disingenuous, I think, to pretend every cow is the same cow and we can just stop and everything will instantly be fine. I suspect if they had no dietary use, they'd require so much care they'd be a niche thing and quite literally all of that would be dumped on the ground or something.