A typed message loses the small hesitations handwriting sometimes leaves visible.

Clean text hides the process that produced it. Handwriting keeps the evidence of a mind at work, the crossed-out first attempt, the slowed letters where the writer paused, the pressure of a hand that meant it. Typed words arrive with all of that sanded off, uniformly confident, so the reader gets your conclusion and loses your uncertainty.

Where the uncertainty matters, put it back in on purpose. Say that you are not sure, that you rewrote this three times, that you almost did not send it. And for anything tender or hard, consider the slower medium. What looks inefficient on paper is often the part that carries the feeling.