Bit vulgar but culturally interesting I thought.
The most popular sandwich spread (bregott, a mix of butter and rapeseed oil) comes in three main variants: “normally” salted, lightly salted, and extra salted.
Proper butter is for cooking but primarily for baking.
I am 45, have been interested in cooking for 20+ years, read many cookbooks and so on. I learned about butter dishes and the idea of having butter out on the counter to make it spreadable from the internet. I dare say that practice does not happen here.
[0] Butter mixed with vegetable oil and stabilized.
Butter preferences around the world are strange.
There shouldn't be any salt in your butter.
There is no salt in milk, there is no salt in butter.
Unless you want salted butter, in that case you can simply buy a slab of salted butter.
The only reason we use unsalted butter is if a recipe specifically calls for it. But it's widely available.
I occasionally also use sold-as-unsalted butter in directly-served applications, because it lets you play with different finishing salts instead of just getting it mixed in with the butter.
Salted butter was a popular spread in restaurants and consumers wanted it in their homes.