Depends on your definition of "good life", but mine is making sure you don't have to worry about shelter, food, or vital medical care. And every industrialized nation can afford that, easily.

What does that equate to, about 40k a year for the US?

$40k * 300M = $1.2 * 10^13, or the whole GDP of the US

Okay maybe that's too luxurious for the common people. Let's say only 20k per year, and to only 200M people.

$20k * 200M = $4 * 10^12, or about the total federal spending for 2015.

So how exactly is the 'richest' nation in the world able to afford this, easily?

You're including children in that.

Also, this would presumably replace Social Security and other welfare costs (or retirees would be excluded).

And finally, people would still be working. I'm sure the taxes I pay would more than cover the cost for giving it to me.

Where is the line drawn for income where above it you pay more net (through taxes) and below it you pay less?

That's true. So why do we feel the need to coerce people into paying into such systems? The more I investigate it the more I think it's because of the power such systems grant the coercers. Consider the uproar over Zuckerberg having the temerity to spend his money on charity in the way he pleases, instead of the State getting to choose.

I believe the reason we need to coerce people into paying is because economically if you don't let people volunteer to pay, it just doesn't work. Excuse me if I don't have the sources for this as it was my Econ PhD friend who explained it to me.

I wonder if the argument against it is something like this: imagine for every person, they have some amount they are willing to contribute to said scheme. However, unless the total amount needed to fund such a project is small, if you don't force everyone to contribute then the cost will be significantly higher per person. Then, because it's higher than what some people want to pay, they choose not to pay although they would have otherwise. After that happens, the price increases more, and this effect continues.

Sure, that sounds entirely reasonable from a mathematical perspective.

But the question to ask is: does that justify the use of coercion to secure funding? I.e., does efficiency justify the use of force?

which is not?

Do we have the infrastructure (or can we build it) and the knowledge or not?