There are different degrees of lactose tolerance, and a good fraction of the world's population is at least somewhat tolerant. Then there are regions of the world where almost all people are completely tolerant, like northern Europe.

There are also lots of dairy products that contain little lactose, from lactose-free milk to cheese. And of course, it's pretty simple to just take lactase pills.

From a completely subjective perspective, dairy products are some of the tastiest foods, and they're objectively a huge part of food culture in Europe. I don't foresee them going away.