By 11th level of play, is it your experience that the base type of weapon dice are the major element of the damage output as opposed to say higher modifiers and tag-along effects from class abilities, items, buffs, suites etc?I don't remember the exact numbers, but without feats on either side (in the above the TWF has Dual Wielder), the GWF pulls ahead at the start, slips a bit at level 4, regains it at level 5, slips again at 6, then pulls ahead (and stays there) at levels 11+.
Cuz, TBH in most every version of D&D I have played from 1E to 5E (and really, most any RPG) the basic difference in weapon damage has rarely remained critical to any real extent beyond the "first tier" or even noticable really at higher tiers than the second.
I mean, if you even add on something as simple as the Warlock Hex adding an extra dice to every hit, the math between x greataxe swings and x+1 shortsword swings changes, right? Sneak attack may be one of the more striking examples early on - where the extra attack helps cover your odds of an initial miss costing you the sneak dice.
In my experience, the characters working two-weapons do so as part of an entire scheme - including class abilities - that help the extra swing and finesse elements pay-off. Especially by tier-3 but really at lower tiers too, that "dice size envy" is not really a problem in actual play as much as it seems in some folk's white rooms of Excel.
Your experience may vary.
But again, if this is a problem caused or exacerbated by feats specifically, adding new feats or tweaking existing ones seems simpler to fix.