yes, multi attack buffs like hunter's mark, Hex, elemental weapons, rage etc.
also you get bonuses from magic weapons and the like, so by 5, you are likely at +5
at level 5, there is a difference of approx 1 dmg per round in favor of 2handed. my calcs say 19.65 versus 20.84 (differs based on attack)
however, the dual fighting is more consistent, since you get two swings.
regardless, this damage is close enough that both are viable.
If you add in multihit buffs, as I said twf performs even better.
And yeah, a level 11 fighter probably wants to use a bigger weapon. But thats the nature of the class. Really, different builds should profit differently from different weapons.
Using a BA has different value for different classes. Many martial classes don't have great uses for BAs.
Point being, dual wielding isnt really that bad. Its not always optimal in every build/situation, But thats how it should be.
this gets improved in ONE dnd, but that has many other changes too, so its a bit of a different beast.
