Unless you mean DS: "democratic socialism" - which is still socialism. Look at the Green New Deal where DS wants to go - control of industry "for the people" by massive expansion of government into various industries.
While you may have a point about the article being American focused, the fact remains that the middle class is expanding and the lower/peasant class is shrinking globally - all boats are rising due to "evil capitalism" and that horrible capitalism, despite being the worst idea ever... is still better than the alternatives that have presented. It's global success compared to the global failure of other "better" ideas is self evident at this point.
Socialism is the perfect theory... until it meets reality... and other setups are in the same boat: Better than capitalism until you look at real world results.
Need to fight cronyism? corporatism? Monopolies with reasonable government controls? Sure... I'm not a PURE capitalism person - My thoughts are based on reality where restrictions keep things reasonable (like restrictions on free speech and owning guns).