It's like paperless offices, for example, where new technologies add new layers instead of replacing what's already there. I don't think it will ever disappear. Not everyone is creditworthy. I can't think of a time of no monetary exchange. There may be very little, but I don't think it will disappear.
Cash has the great advantage of being fungible.
It's good for everything. Money has almost disappeared now. When income taxes disappear. The underground economy is still thriving. You're really down to cash in the underground economy and for the lower income strata, where there's a lack of trust in people's credit.