It's about respect for the other person, as I see it. You wouldn't be a little miffed if your wife of 10 years sent you a "k thx bai (link to divorce papers)" instead of talking in person?
Context is everything. Yeah, your wife of 10 years deserves the face to face, more than once. A dude I dated for a few months that showed no emotional intelligence specifically told me he'd prefer a text. I obliged when I realized it wasn't going anywhere and I didn't want to keep up a casual relationship. He then asked to talk in person, though, and I again obliged.
I think its basic courtesy to put even a little effort to something as important as a breakup. Not doing it face to face or at least in a call removes the interaction completely. It's taking the easiest possible path in a situation that will certainly affect the other person in a significant manner. It's cold. Using a LLM for said text like in the meme is even lower effor and leaves the recipient feeling utterly worthless.
Basically the same thing as getting fired via email.