> The Superdracos are powerful engines but they don't have anything near the delta-v to always return to land after an abort even if you fill the entire Dragon with propellant. So you'd always need the chutes anyway.

Not sure that's true. The chutes bring the speed of the capsule down quite a bit, just a short burst of the dracos at the last few feet could allow it to softly land and wouldn't require much propellant. This is exactly what the Soyuz does. My guess is that this approach was rejected by NASA (not SpaceX) due to complexity rather than feasibility.