Yes, that's my point. Funded and self-sustaining are opposites.
It only provides that answer if when you said "people" you meant "Sanders, Warren and Gillibrand". Bringing back postal banking is a no-brainer since it wasn't a burden on the taxpayers. But this is lpetrich's thread and it's about the Ocasio-Cortez/Tlaib proposal, not the Sanders/Warren/Gillibrand proposal.
"EXCLUSIVE: @RashidaTlaib and @AOC are proposing a new bill that would foster the creation of public banks across the country — with the aim of encouraging investments in public resources such as affordable housing and renewable energy projects. ...
...establishing an infrastructure for liquidity and credit facilities for them via the Federal Reserve, and setting up federal guidelines for them to be regulated. Essentially, it would make it easier for public banks to exist, and it would give some of them grant money to get started.
... public banks, which theoretically would be more motivated to do public good and invest in their communities than private institutions, which are out for profit. ...
... establishing the Public Bank Grant program administered by the Secretary of the Treasury and the Federal Reserve Board which would provide grants...
... fund public infrastructure projects...
...the passage of The Public Banking Act would provide a much-needed financial lifeline to states and municipalities...
She said that she also believes public banks could facilitate the use of public resources to construct “a myriad of public goods,” ... “Public banks empower states and municipalities to establish new channels of public investment to help solve systemic crises.”
... They could also facilitate easier access to funds for state and local governments from the federal government or Federal Reserve.
... or FedAccounts, where everyone gets an account with the Federal Reserve through which they could receive direct payments from the government, for example, during an economic crisis.
"California just legalized public banking, setting the stage for more affordable housing " - "Supporters say the change allows for funding infrastructure demands or providing loans to public agencies at low rates"
So lpetrich, Ocasio-Cortez and Tlaib are clearly not thinking of a self-sustaining system. What they're advocating will plainly be at ongoing taxpayer expense. That's also what Jarhyn is evidently thinking of:
... Fifth, it means that the public is finally capable of engineering loans and interest that actually make sense based on needs rather than "risk", the latter being a concept that is really justification for charging more of those with the ability to pay less. ...
But I take your point -- some people are thinking of more expensive systems than others. It's a mixed bag. Sanders' and Gillibrand's moderate proposals should satisfy Jimmy Higgins' concerns, for instance.