Generous welfare policies can only operate in small, homogenous countries because if you open the borders, immigrants flood in and then sink the boat.
If society is to be made over into a more socially just configuration, the Democrat socialists elected to positions of political authority through a democratic process must now introduce government planning to introduce comprehensive collective group fairness.
The elected socialist politicians and the appointed bureaucratic managers in the government departments and agencies must now formally classify and categorize everyone in society in terms of social class, race, gender, and related “intersectionalities” to determine who has unjustified “privilege,” and who has been exploited, underrepresented, or in some way discriminated against for the undeserving benefit of others.
This will inescapably devolve into a plunder politics of groups versus groups guided by their respective politically positioned leaders. Who will get a new housing project? What group will secure more government jobs?
Which sector of the economy will receive increased government budgetary funding to ensure investment and employment opportunities for a still-underprivileged minority in a particular region of the country? What will be a fair wage for certain types of work, possibly based on race and gender deservedness? What is a reasonable profit margin or return on investment in regulated private industries? Which products will be either subsidized or produced directly by a government planning agency?
Regardless of the intentions or naïve beliefs, a system of democratic socialism cannot escape imposing commands and controls over economic life any noticeably different than those that were in existence in the old Soviet Union.
You make some valid points. Others seem exaggerated or off the mark.