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?