Having a culinary background, I know that bakeries only use unsalted butter because it is scientific process and additions to the butter can ruin the results.

Hot kitchens prefer unsalted as well because a professional chef wishes to season food to perfection without unknown variables of butter salt content.

But, butter pats for a dining table typically use salted butter. We would also buy salted butter in bulk, whip it and pipe it into florets for the dining table, sometimes adding honey or other flavoring as well.

Preservation is my guess

Preservation. Everything used to be pickled or salted back when.

It's used where the bread isn't salted. To be tasty you need to add salt to one or the other. I personally like salted butter, but it's not available here.

I was always told the salt hid any rancid taste, if the butter gets old. Don't know if that's still a thing. I do love Himalayan pink salt on butter tho!

It's good.

Himalayan salt is just rusty Paki salt, nothing special.