When most people think of socialism, they think about the various forms of authoritarian socialism. In these scenarios, the system tends to devolve from state socialism into state capitalism before falling apart, as what happened to the USSR.
There have been a handful of highly successful regions that used libertarian socialism, though they often met their end via invasions. One such example of this is Revolutionary Catalonia, a fairly large region that sprung up during the Spanish Civil War. During their existence they saw massive improvements to quality of life and literacy rates, however they were destroyed around the start of World War 2 by fascists.
An example of market socialism would be Yugoslavia, and while it was destroyed by an increase in nationalism leading to wars, they were doing better off than other similar regions during the same time period prior to that.
A modern day example of libertarian socialism would be the Autonomous Administration of North and East Syria. Despite being under constant threat of Turkish invasion, they've managed to do quite well for the region. They also played a crucial role in the defeat of ISIS.
A lot of the stuff people hear about socialism these days is propaganda from those in power, as any major successful socialist countries would threaten to topple their power. It's why the USA's CIA has repeatedly overthrown democratically elected leaders in smaller countries. They don't want people to contemplate possible alternatives to the current system.
Every system has its downsides, that's why it's important to compare it to other systems in similar countries. You can find plenty of bad things that have happened in any country regardless of its social and economic systems. I see lots of people point to one bad thing in a country and use it to dismiss the entire system.
Also, a common tactic of authoritarians, including fascists, is to call themselves socialist even when they are anything but. The classic example of this is Hitler's National Socialist party, who killed the actual socialists in the party during the Night of the Long Knives. If calling yourself something was enough to actually be that, than North Korea would be democratic and China would be a people's republic.
Authoritarians call themselves something that's popular in order to garner public support, try not to fall for it.