its true for me.

I have trouble focusing on speech, so i often end up responding with "what?" then a few seconds later, it makes sense and i can respond. Writing is easy to injest at the rate your brain wants it.

For me, at least, reading offers significant advantages to listening when it comes to intake speed. I can trivially rewind if I need to, I can more readily skim content that I understand, fewer comprehension failures due to accent/pronunciation issues, etc.

I often notice that I read transcripts significantly faster than the audio time...

That's only natural. That audio time is based on the speed of the speaker's cadence. If it's a live presentation, there tends to be pauses, ums, uhs, deliberate pauses and what nots while the speaker gathers their thoughts or allows a statement to sink in before continuing. If you were to speak at the same pace you were reading, the audience would probably not be able to follow.

I was more thinking about radio talks, but, yeah, a conversation needs even more of those !

Captions appear at the same average rate as the speech they're captioning.