Despite it's obvious benefits, the world is not the same as it was lo those many years ago. Times change, we need to adapt or die. You are seeming to suggest that we have reached the pinnacle, but what if we can improve the state of the world to the benefit of more people?
Basic market forces haven't changed though. Consumers want better products at lower prices. Businesses want to make the biggest profit possible on the products they sell. Employees want the most salary for the least time/effort. Employers want the most labor output for the least cost.
These basic forces operate the same. Haven't changed. Aren't likely to any time soon. Socialism as an idea has existed since the beginning of the industrial revolution. It's been tried many times. Every single time it's actually been implemented it has resulted in a reduction of productive improvement, reduction of relative standard of living for workers, and an increase in authoritarian control over those workers (ie: less liberty).
It's extremely telling, when the biggest concern over socialism is the things that said authority will do with it's power once it has purchased it with promises of free education, free housing, free food, free health care, etc, that the current proponent of said system openly states that the fact that Castro was a brutal dictator is somehow offset by the fact that he improve literacy in Cuba. Um... That's exactly the problem. The "cost" for that is having to live under authoritarian rule, and just kinda hoping that it doesn't result in gulags or something.