The working class practically does not exist. Instead of working in their factories, workers are spending their time selling things in the flea markets. In any event, it is almost impossible to organize a big strike since real trade unions do not exist. The second thing is that Serbia is an agricultural country and this is why people are not hungry. Regardless of its catastrophic agricultural policy, Serbia has enough food, thanks to the rich soil, especially in Vojvodina.
People can survive, even if it means that some are forced to eat nothing but bread and milk.
And finally, the third thing that helps the regime is the media isolation. People are given false information and are consequently easily manipulated. Well, if you are talking about Milosevic and his family, it is very easy for them to do it since they belong to the top layer of the nomenklatura and are wallowing in money. That wealth was acquired by plundering the country over the last ten years. If we are talking about the economy of Serbia, then it has collapsed.