I prefer games with voice acting, ideally fully voiced, because tone also plays a part in understanding a character's emotions. With just text, sometimes the emotional nuance can be less clear. Some games may not have the budget for full voice work and might only include a few interjections or...
I'm used to using light mode because it makes the text appear clearer. Dark mode tends to make me feel like the focus shifts away from the displayed text, so I'm not very comfortable with it and have continued using light mode.