the left button would be better represented by saying 'capitalism doesn't work because it naturally brings about a scenario in which the most selfish people have the most power'.
Socialism always refers to places like soviet russia... As several prime ministers of europe have already went public stating multiple times, the EU and its member countries are not a socialism, they are all capitalist nations
Jacobin has a great "ABCs of Socialism" primer for those new to the concept,
and even more importantly CrimethInc has a pamphlet called "To Change Everything" that you can find digitally here:
https://crimethinc.com/tce