Nothing lasts forever, and not everything is a slippery slope. Historical context is also important.
For example, some people have this notion that the Roman Republic was somehow "good" and the empire was "bad" solely because the Senate had power in the Republic, and voting = good. But in actuality it was a pretty messed up system of government because only Romans (literally people in that city) got a vote while the rest of the Italian peninsula got no say. And yes they fought a war about this and the "good" side lost. Voting was heavily weighted towards the upper classes, too. The empire wasn't all bread and circuses, but it did scale better, which had some pros and cons too :). But for your average inhabitant of the Italian peninsula you had no more or less say in how either government ran.
Dictatorships can be quite a mess when it comes to enforcing laws unrelated to keeping power. These laws tend to turn onto soft of weapon to be used or not depending on whether you want harass someone or not.
This happened in both Nazi system and Communist system. Both were high corruption a lot of petty crime normalized society (and a lot of other petty crime severely punished depending who done it and what was done).
