I've never seen or heard of this implication you speak of. True the people on Earth live a materially comfortable lifestyle, but where are you seeing that they're not providing for themselves? Everyone would seem to be employed (or attached to someone who is), Bashir's father bounced between jobs, but he had jobs.
Because they basically say this in TNG? That there is no poverty, no private ownership etc. You still have jobs but people don't work for money, they are most likely repaid in credits for their labour/energy.
How then (under the system you describe) does the bar acquire the bar itself? The building (or space) furnishings, supplies, power, food, what not.
They're basically provided them and sponsored by the Federation I mean, USSR and such still had bars, restaurants, night clubs etc.
And suppose someone wanted to emigrate from Earth, and establish themselves on a planet that doesn't have the system you describe? With no accumulated money, how would they pay for passage and set themselves up.
They petition the Federation for resources or engage with the non-Federation economy.
No matter how hard someone works under your system you could never save up. I take it you would be unable to invest and grow your money, because apparently you don't have money to start with.
And? You live in a society with completely different material conditions. You do not need money. You do not need to invest. everything is provided for you. TNG clearly states there is no private property within the Federation economy. The concept of capital and capitalist investment is completely alien to Jake.
Why do you need to "Save up to invest"? You don't live in Capitalism. Credits exist, but socially necessary labour and energy, not capital is what credits represent.
Kirk: "Carter Winston has acquired a dozen fortunes only to use his wealth time and again to assist Federation colonies in times of need or disaster. "
Again, Private business exists outside the Federation. So it's easy for Carter Winston to interact with the non-Federation economy and make money.
In TOS we see that Replicators don't exist (but synthesizers do) and resources are still carted around by cargo ships. There are plenty of reasons a colony may need to interact with the non-Federation economy if say, a cargo ship was destroyed by Klingons.
Also in TOS, the writers nor Roddenberry had really conceived of a larger Trek setting. I mean, for much of TOS, the Federation doesn't even exist. Most of Star Trek's world building started with the films and TNG and thus we have to project back onto TOS the worldbuilding that came later with the New World Economy.
"I disagree with capitalism so I am going to project my own beliefs and values (communinsim/socialism in this case) into what I believe Star Trek is preaching."
The Federation is clearly a Socialist society and not Capitalist. This is pretty clearly stated time and time again in TNG, Voyager and DS9 if you listen to what they are actually saying when they're spouting clearly Socialist concepts. The Federation characters in Star Trek from TNG to Voyager also clearly talk about Capitalism in a extremely negative and historic tone.
It's also backed up by the claim in several writings that Majel Barrett said Gene Roddenberry was a Socialist/Communist in his later life and the claim that has made it into several Trek books that TNG setting was inspired in part by Posadism. (A fringe, sci-fi alien Trotskyist sect who's vision for the future, happens to near be 1:1 identical to how the New World Economy and how humans contact aliens comes to be in Trek)
If you want to know how the economy in the Federation works. Read Socialist and/or Technocracy economic theories, because it's clearly what Roddenberry and the writers did.
I would suspect this video was likely watched by Roddenberry because I know it was very popular throughout the 80s and elements of it do seem to appear in Trek. (Deals with Money vs Credits at the 40 minute mark)