Young people reject a business-dominated society and demand Socialism, but concretely what is that going to mean?

One proposed meaning is "Liberalism with a spine". What does the spine mean? It means keeping a sharp and suspicious watch on attempts by the rich and businesses to reconstitute their power.

To keep any sort of Socialism from being resubordinated to business, we need to put an end to the political power of business. The bigger a business is, the more political power it has, so we need to split big businesses into small ones. Then we can stop them from ruining or subverting the other measures we take.

My proposed progressive tax on business could help.