This is a late response, but a good example.
I use a balanced dongle to drive current-hungry DCA planar headphones. But I also have an Ety ER4XR IEM for convenience. On my Lenovo Thinkpad laptop, I can plug the Ety IEM into the headphone jack, and it's fine for streaming the news. But compared to driving the IEM from the dongle, driving it from the PC makes it sound thin, insubstantial and kind of grainy.
I don't know why. Surely the IEM is not a big power demand. Both the on-board PC audio section and the balanced dongle go through the same EAPO Eq profile, and the difference in SQ persists if I turn off Eq.. So I don't know why, but I know my PC audio just doesn't sound as good as using a quality dongle.
So it's probably true that the on-board audio will sound ok in many cases, but perhaps not all cases.
(My Surface Pro does sound better.)