I'd say under 20%.

I play this game duo with a friend (where, like for d&d - it's hard to match schedules) and solo with 2 characters (and a third to follow after). I obviously like playing it with my friend, but tbh I think I like playing it solo just as much, or more. Both my solo campaigns and my duo one are pretty much in sync, but in my solo stuff I get to do what I want, with no consequences. Imagine if your d&d table is good-aligned, but after the session you get to go home and play the same session again, with your chaotic party, who doesn't take shit from town guards or uppity priests, who intimidates instead of persuading, who loots the dead king's body instead of saving him. So yeah, you can have both types of fun :)