Treantmonklvl20
Explorer
Consider that a wizard's familiar can grant him advantage on GFB, but not on more than one weapon attacks. Familiar disproportionately benefit cantrips over Extra Attack/dual wielding.
It is a matter of some long standing debate whether a familiar, which is unable to take the attack action, but can deliver touch spells can in fact provide advantage on attack rolls. You are likely to get different arbitration from different DM's.