Combat

^ that's a big reason yes. It's the main reason actually. THe two things you said honestly sorta go hand in hand. However Ejoyment/fun is a very arcane concept as everyone finds different things compelling. SIlent Protgas go for an audience that would be or feel it is jarring to ahve the character speak etc. As soon as that character talks, they are a character in your eyes. They have a veiw etc... THis is why it's more common in RPGs etc, at least if they want you to feel as if Y...

*YOU are the protag.

They're pants characters. You wear pants. Pants don't speak.