I don’t understand the writing on the cups

Hello, I don’t drink at Starbucks, nor do I go to Starbucks for anything except a black coffee if I’m in the city and need a bathroom. However, I am here from Wawa Reddit and after a brief scroll I noticed that it seems to be company policy/it’s a huge thing to write on cups. I can’t comprehend this. Here are my inquiries:

-why? Like what is the purpose of this?
-how? How is this rolled out? Isn’t Starbucks about timeliness and getting orders out? Do you HAVE to write on a cup, or is it like a ‘you can if you want to but if you don’t you’re going to get weird vibes from management’? This one is my biggest one because I can’t comprehend how, in any capacity, this is a good use of time and labour for a company who seems to priotise profits over everything. Like, I just don’t get it. Is there someone who is hired specifically to draw on cups? If there isn’t, does each worker have to hand write a message or drawing on the cup? Doesn’t that take out of the time they could be using to clean/make drinks/rest/go to the bathroom/literally anything useful? Does Starbucks have statistics that show that a handwritten message makes consumers a diehard Starbucks fan?

I just don’t understand. Also I’m sorry about Starbucks, I don’t know I don’t shop here and I’m not in the culture, but man it seems like Starbucks workers could use a hug.

Thanks!