In American businesses we call it "pleasantries," which is a completely ridiculous concept to most people outside of America because it's incredibly fake.
This entirely has to do with American consumer society and the way that it values the customer over the employees and staff. Such a concept originates actually thousands of years before America even existed, and its only implementation into American business models is that of coercion. Otherwise, yes, it's complete and total bullshit.
The customer and employee don't actually give a **** about each other at all, their interaction is entirely transactional. I give you the product, you give me the money, I bid you farewell, end of transaction.
Alternatively, the customer can banter a bit with the employee, this commonly happens with either the affluent, the elderly, or the aloof, and if you're a particularly unlucky cashier it will be all three in the same person. Now where it gets weird is that even when this happens it is still one-sided. The customer is allowed to be that way if they so are.
But if I as the employee begin to break customer service protocol and be totally honest about my day or feelings in brief gest, that's informal and potentially unacceptable or inexcusable, depending on which company I work for.
So since I'm stuck in this bullshit trap, I try to interact with customers as little as possible, in order to keep the line moving at a quicker rate, so that I can go about my day.
I've had several different European friends throughout the years explain to me how it's ridiculous, and they're right, it is ridiculous. Customer Service and Business Pleasantries historically have their origin like way back on the Silk Road-era of trade routes. Which makes sense for then, because if you travelled hundreds of miles through a variety of dangerous situations, you do kind of need to make enough to be able to make at least enough for supplies for the long road back. So it truly is an archaic concept, but it's still an archaic concept that works, and because it works and it's profitable, that's why it's streamlined here.
My boss and I joke about it all the time.
She says: "I wish I could just be realistic and be like: "No need to come in, there's nothing essential or interesting here, just slip your money under the door, thanks."