Yeah there are gaps.There are two depending on what you do with those weapons. Duelist and Two Weapon Fighting. Meanwhile nothing actually uses Versatile.
In fact there is the same gap there for both the Zorro types and the Versatile types - nothing for a one handed weapon and empty hand/mail palmed glove regardless of whether you want to use the free hand to grab people or swing on ropes and chandeliers
That's my point.Not even close to true other than that there are fans who don't realise how much of the Swashbuckler's schtick is unnecessary in 5.24 thanks to steady aim and vex weapons.
First one of the Swashbuckler's level 3 abilities let's them walk away from a foe without taking opportunity attacks - the literal opposite of "attack it and stay there".
Second that ability to walk away is the only damage mitigation the subclass brings.
Third the swashbuckler dies horribly if they get double teamed. They lose their extra sneak attack if two foes are in melee with them.
The swashbuckler doesn't tank or join the fighter and barbarian in the thick of it. They either cut through the combat using monk-like mobility to get to the caster or archer in the back or duel people on the edge
The Swashbuckler subclass is a kludge to incentive single handed Finesse weapons and light armor