First, you have to define socialism. Much like capitalism, different people have a different perspective on what the term actually means.
One half of my family are from an ex-Soviet satellite. My great uncle used to say that socialism was what the communist overlords called communism in countries where they couldn't eradicate religious belief. And I think he had a very valid point there when you look at socialist "projects" across Catholic states in South America and Muslim-majority countries in Central Asia and the Middle East. I'd also include Poland in that as well.
The problem with socialism is that it doesn't scale well, but it works wonderfully in small instances. Every family is essentially a socialist enterprise of each according to need, each according to ability. This approach also works well for small villages and towns with a coherent sense of community.
But when you try to scale this to even a regional level, you lose the relationship bonds between individuals that provide the information that supports a sense of justice and fairness. This is why so many ex-socialist and communist states constantly reinforced a sense of patriotism and nationalism - - to recreate that sense of familial familiarity between citizens so as to avoid a sense of injustice.
Of course, it didn't work. And in order to support that sense of "parameters", there was next to no migration permitted in, out or within such countries.
I've often wondered why people think socialism can work on a state-wide level. What you essentially end up with is a "socialist" cabal at the top of the political pyramid that decides all policies, regardless of whether those policies are actually sensible or not.
And that's because people disagree with each other. Crikey, adults can't even live in house shares with each other without problems. Someone always does more washing up than someone else. Someone always leaves the bathroom in a state.
With socialism at state level, you are simply scaling this same problem to cover millions of people. So naturally, the washer-uppers will favour a system where you get out what you put in and distrust a system that doesn't recognise their efforts.
Another thing I would say is that we don't really live in a capitalist society in Britain. It's a corporatist system, with a side helping of "sop" in the form of free to access education and healthcare.