As long as we have people as part of the decision-making process, we will never change. I wonder what will happen when Google's mainframe starts making the decisions for us.

This goes back to the very thing that got me into Socialist thought, the mixture of Socialism and Technocracy which was called the Resource Based Economy (RBE for short) by Jacque Fresco, founder of the Venus Project. In theory, the best way to run society is not by the authority of humans or AI, but by the "authority" of methodology with the goal of creating the best outcome for everyone and everything. In other words, no one makes the decisions at all in an RBE, we instead "arrive" at decisions by weighing the options and using various processes to come to a conclusion that works for everyone. What are these processes? Idk, it depends on the specific problem you are trying to solve and there is really no one true way to solve all problems, but the idea is to not have anyone or anything actually telling us what to do based on their/it's own biases and interests.

who pays for the free lunch?

There is no monetary system in fully-realized socialism.

This is way more complicated than you want it to be though. You have never been interested in putting any real thought into it, you want to use capitalism logic to debunk a type of logic you aren't even familiar with. Imagine Adam Smith trying to explain his ideas to a die-hard Monarchist who doesn't even take the notion of capitalism seriously. That is very analogous to how most capitalists approach the idea of socialism.

You want to look at how people think now and say "this will never work because people need to be payed in social constructs to feel rewarded". The change in culture has to come first though, and it is very incremental in nature. There is no socialism without the average person becoming more rational and wise, enough so that self-governance and communal governance is feasible and so that equality can happen without it being artificially forced. To simplify for your capitalist brain, just think about the "socialistic" policies you always talk about and the fact that you are giving something to the system without direct reward for the long term benefit of both yourself and the community as a whole.

You have to be the Dumbest Bastard in the World there little boy. There is no such thang as a Free Lunch but your head is to far up your ass to figure that out.