It has not. Skepticism about specific doctrines may, at most, have been a first step (nothing more) towards the resolution of scientific problems. But skepticism “in and of itself”, as you say, has done absolutely nothing, since it does not have a coherent target.
So-called ‘skepticism’ isn’t really about science or truth, so much as it is just a way of dummies to peacock. Self-described “skeptics” are not skeptics: they are the least skeptical people you will ever meet, when it comes to accepting whatever the going lines.
Skepticism, when significant, has be skepticism about some very specific claim (and being ‘skeptical’ about ‘religious’ or ‘God’ won’t do the trick, since that is far too general and otherwise suspect).
Finally, it isn’t really skepticism that leads to breakthroughs. It is cases of suddenly realizing that some previously unquestionable ‘truth’ was indeed questionable, the classic example being the concept of absolute simultaneity.
If a position is there for people to be skeptical about it, that means that it is no longer a breakthrough. It is just idling.
It is sudden reversals of position that lead to paradigm-shifts, not bureaucratize ‘skepticism’ about age-old ones.
Rule of thumb: ‘I am a skeptic’ means ‘I am a poser; avoid me like the plague.’
Second rule of thumb: If they say ‘I am a skeptic’, you say: “go to vocational school.’