When I hand write taking notes, I am indeed forced to slow down, and it's maddening. I'm busy trying to figure out how to condense the ideas into something I can quickly write, and in the meantime the lecturer is continuing and I've missed something important they've just said.
I genuinely do not understand how people find it helps them to handwrite notes in a lecture. If I type on my laptop, I can do that "mindlessly", which is beneficial because then I have enough of my brain free that I can also understand what the lecturer is saying. Ask a question if I have one, etc.
If I'm hand-writing notes in a notebook, I can't do any of that. I'm so focused on trying to get the stuff down that it's using a lot of my brain that I'd really rather be using to actually think more deeply about what is being said.
I'm genuinely so baffled by people who find that hand-writing notes helps them understand the material better. I used to assume they were terrible typists, but I don't think it's that.
But for example, with your comment, you say that when typing notes, you can transcribe word-for-word without knowing or thinking. But... why not just actually pay attention? Isn't that the whole point? Why do you need slower handwriting to force you to actually pay attention? That's what confuses me so much. I pay attention by default. Writing notes by hand takes away from my attention, because I have to give attention to that.
It kept me listening. When I was on minute 70 of a boring lecture I started daydreaming. If I was writing even minimal notes, I'd need to briefly consider each idea and decide whether it was worth recording.
Writing notes by hand feels like it etches the concepts into my brain in a way that listening alone does not. Typing does not have the same feel.
I have never learned how to do something substantially difficult (math, foreign language, any science, or memorizing a substantial amount of content for a humanities course) without handwriting it. I remember in 8th grade latin, I copied down conjugation charts onto a chalkboard over and over until I had them memorized.
I cannot do university level mathematics without writing it down by hand.
My typing is much better than my penmanship, but it doesn't tend to make topics stick in my brain in the same way that handwriting them does.