Democracy developed in a world of totalitarian regimes, and mostly thrived because having officials vulnerable to election cuts down on corruption and incompetence while building government legitimacy and stability.
Totalitarian states tend to have a good run, where they have a good leader and energetic administration, then they become lethargic and dysfunctional, and because there's no mechanism to correct this, they start falling apart. (However, this can take centuries).
As an aside, I don't think the West has ever been particularly keen on democracy. I think Israel is the only democracy that has ever received substantial military and economic support. For dictatorships, this kind of support is basically routine (see Egypt, for a typical example).
Totalitarian states tend to have a good run, where they have a good leader and energetic administration, then they become lethargic and dysfunctional, and because there's no mechanism to correct this, they start falling apart. (However, this can take centuries).
As an aside, I don't think the West has ever been particularly keen on democracy. I think Israel is the only democracy that has ever received substantial military and economic support. For dictatorships, this kind of support is basically routine (see Egypt, for a typical example).