We're gonna get there eventually mate. You presume because advancement has been slow in the past (much more hindering religion then.) means it shall ALWAYS be. I think not.
Human history seems to be cyclic rather than linear. Advances have come and gone many times in the past. Why should this time be any different? In fact, we've advanced to the point that our technology infrastructure has become 'fragile'. Meaning that we can no longer build the tools without other tools.
If all the power grids went down, we'd probably see 90% of the human population die off. This equates to total killoff in urban areas, with more rural areas and third world nations having a higher survival rate. The start would simply be a lack of sanitary facilities and food in population-dense clusters, leading to panic and people dying off in droves. Then diseases start hitting in full force, Cholera from lack of sanitary drinking water, insect and vermin vectored diseases like Malaria come next as the populations provide opulent breeding grounds for the vectors and can no longer control their populations. And, of course, people killing others off for resources such as clean drinking water and food and just plain paranoia and panic.
Quite frankly, we would regress to a pre-Rennisance technology within a decade simply due to being unable to maintain our current level of technology. The more technologically advanced cultural areas will die off, and surviving population clusters will be in the areas which never depended on technology as much.
Progress is by no means inevitable. Never underestimate the power of stupid people in mass quantities, which is pretty much any government in existence (well, totalitarian regimes are a single very stupid person rather than a bunch of stupid people, but it amounts to the same net level of stupidity).
As has been said before... "History may not repeat itself, but it certainly rhymes". Also: "I know not with what weapons World War Three will be fought, but World War Four will be fought with sticks and stones".