You'd be surprised how lightly a fish can pick up a soft swimbait dragging slowly across the bottom. A lot of guys have the misconception that every bite is this bone jarring car crash. Quite the opposite.
The other thing is being able to tell weeds from a soft bite, running into a log instead of a bite, being on mud or in rocks. Doesn't necessarily help with bite detection all the time but definitely lets you know if you are where you need to be.
Big baits, big soft baits particularly, are not any different than fishing a jig really. I want to be as connected to what that bait is doing as humanly possible. It instills confidence if I know what is going on when I can't see it.