Is there really players that read texts when they play computer RPG saying "I will tell this line, but in a sarcastic tone because that's how I'm role playing my character" or "Oh my character is telling this in a humorous tone because he find it fun even if it is dramatic" ?
I guess even "hardcore role playing players" are just reading the story... but I may be wrong of course.
Yes. I absolutely add to the text. I pick an option but also think of : What's my character's intention when saying this? Why? How are they saying it?
That's why not-overly-specific-characterizing dialogue options are better, in my opinion. Overly specific options do require various amount of mental gymnastics (in a way that's not as fun and more immersion-breaking) when there are no options that fit my character. And that happens a lot with BG3.