@FaIIenAngeI777 It’s the fact that you can edit it. Just think (this is a psychological test) about writing a casual letter to someone you cherish or have a large amount of respect for (I’d say grandma or something but not everyone can envision it due to various reasons). Do it in 2 ways:
One is through email
One is via actual post-lick-that-envelope mail.
You can already guess where you’d likely make more mistakes. It’s the propensity of your brain to associate the edit with internet and not-easily-edit with postal handwritten. Besides that point, internet has all the tools (words, symbols, characters etc) at your disposal. For handwritten stuff you need to actually use more brainpower to make up the letters and words which in turn affects your overall letter.
This is a thought experiment and may differ from person to person tho.