Yeah, the robot/engineering part is cool, but the end application is just yet another junk mail gimmick, and a pretty dull one at that, which is hard to get excited about.
Decades ago I talked briefly with a startup that was doing something similar but using calligraphers in China. The founders were nice but I passed for the same reason.
Because the only reason to do it is to fool the recipient into thinking a human wrote the letter. It's certainly not more readable or efficient than laser-printing Helvetica.
It’s a cool project, yes. But getting even poorly faked versions of this with a “handwriting” font is super annoying.
The purpose of this is to deceive the recipient, plain and simple.