Your problem is that you don't see that all that "abundance" of food was grown by people, transported by people, prepared by people, and served by people, and none of them are your slaves. If they had the chance to get their own free shit without having to do all that labour, they totally would. But then who would remain to do the work?
The all you can eat restaurant stays in business by charging enough for meals that they can be reasonably sure that you'll won't eat more than the food is worth. However, that doesn't reduce the value of the food to zero.
Let's try another thought experiment. In my experience, all you "shit should be free" types assume all value flows from the state. That's wrong; it flows from individuals that are taxed by the state. Why don't you, as an individual, open an all you can eat restaurant where people can eat for free? Why not be the change you want to see?
Your position is only tenable if you are part of an upper class that has others in a lower class working for them, and involuntarily donating the fruits of their labor. In another word, you wish to reintroduce slavery.
Your problem is that you presume food is abundant because it just is. Reality is that food is being produced, by people who want to be paid for it. Take away that payment, and they will stop producing.
Food is abundant because of the Haber process [1] and other industrial-era improvements to food production. Only about 2% of our total labor output is required in order to produce all of our food [2]. The government subsidizes 10% of all food production and purchases [3][4]. If we already can afford to pay 2% of our population to make all of the food, and we already give away 10% of it for free, then it seems like we could reasonably discuss giving away more food for free without disenfranchising farmers.
Edit: I just realized that you might be clueless about this entire corner of sociology, so I should tell you about government cheese [5]. WP says, "Government cheese was created to maintain the price of dairy when dairy industry subsidies artificially increased the supply of milk and created a surplus of milk that was then converted into cheese, butter, or powdered milk." In other words, the government put too much money into making food, and gave away the surplus, and this has been happening continuously for decades.
[1] https://en.wikipedia.org/wiki/Haber_process
[2] https://csanr.wsu.edu/we-are-the-98-percent/
[3] https://en.wikipedia.org/wiki/Agricultural_subsidy#United_St...
[4] https://www.ers.usda.gov/data-products/ag-and-food-statistic...
Your link specifically says that 2% of the labor force are farmers. It does NOT say that all people involved in the entire chain of activities that ends with food sitting on your plate represent just 2% of the labor force. Other people involved are the people who make the fertilizer, the people who package the food (for example, by canning it), the people who put it on store shelves, and the people who transport it all at each stage. Your fourth link has a helpful chart: actual farming represents a mere 7.6% of the cost of the food.
Your links do not establish that 10% of the food production was subsidized. Even if they did, a subsidy is not free money; it is paid from taxes that everybody pays. Thus, assuming the 10% number holds up, the only conclusion that you can draw is that 10% of the cost of food production is socialized.
It does not logically follow that if we pay a certain percentage of the labor force for food production, we can therefore afford to give the food away for free. That assumes there is undue profit in the chain that could be removed. Such profit might exist, but you have done nothing to establish that as a fact.
Sociology is not the science of government cheese. Even so, the overproduction only represents yet another failure of central planning; the free market would not have made such a mistake. It is public money, taken from tax payers, and spent on producing unwanted goods. Nothing about it is free.
However, that 'sociology' does explain a lot about why you are so horribly misinformed about how the world works.
For example, how can an all-you-can-eat restaurant stay in business if they let everybody eat as much as they (rationally-economically) want to eat, and labor has to be paid? If food is abundant, then the cost of each individual patron's meal is negligible and it becomes a question of whether enough people come through the door to pay for labor.