I'm not into the "Federation is communist stuff", but it's an interesting way at looking at Trek society, that makes it both creepy and fascinating.
Remember, Marx talked about "the end of History," wherein human civilization will reach its logical or most rational conclusion...communism (in the literal/doctrinal sense). The Federation can at least be compared to this. Where everyone is free and equal in a mutualistic rather than materialistic society.
"Working to better ourselves and the rest of humanity" is definitely a socialist idea, although not hardcore.
The food, clothing, and etc, are all provided automatically by replicators and machines (which may be provided by the government.) (Picard said no need or want.)
And you have to wonder if the earth government made this decision for the people, or if the people voted to do this.
(I tend to believe the people voted for it)
They can enjoy these things fine as long as they reside on earth, but if they leave it to join a culture that trades goods for currency--they'll be helpless.
Trek doesn't say all of this outright, but it is strongly suggested. As I pointed out, Jake Sisko says as a human
he doesn't have any money.
He wants to "buy"-- actually purchase an item from someone on the station. He cant. He doesn't even have a few credits, absolutely nothing.
As a human he lives off replicators, which provide what he wants.
So earth is like some sort of garden of Eden that you have to live in to enjoy, but step out of it, and you're into the wilderness of money, working, and paying bills.
This is all theory, that I pieced to together but it does fit in certain places.
Notice how other cultures know about replicators, and they still trade in currency, and they have a definite concept of being poor.