I await your plan for a society with no markets.
However, some financial products emerge naturally between individual parties, such as credits and small-scale loans. I think the most noticeable loss would be the lack of mortgages (i.e. having to pay for a house up front). No simple means for online purchases would also be inconvenient (Bitcoin is still not a viable normal solution).
Didn't Ireland have a complete and total bank strike for a full year in the 1970's, with absolutely no negative side-effects?
Mortgages aren't great but having to pay for a house up front would move empower rentiers even further.
I just think you need to be specific, you're already down the path of realizing that some (but not all) of this is like laws of nature, saying that there's no value in a financial sector just seems ignorant.
May 7 – July 30, 1966
May 1 – November 17, 1970
June 28 – September 6, 1976
According to Wikipedia[1], the banking strikes had little affect on the preexisting economic woes, namely both high unemployment and inflation.
[1] https://en.wikipedia.org/wiki/Irish_bank_strikes_%281966%E2%...
Ireland in the 70s was not a prosperous place, and trying to pay for things with second and third and fourth-hand uncashed cheques was a massive headache for everyone.
Jokes - there's nothing wrong with a sensible financial sector but our current over-financialised world of financial speculation with the public being required to bail out financiers is dangerous and needs to be reigned. This to me is just another example of how useless a good chunk of modern finance is