And each of those individual operations must be preserved. The example of account credit/debit is not used because it reflects reality 100%, but because its a s

And each of those individual operations must be preserved. The example of account credit/debit is not used because it reflects reality 100%, but because its a simple-to-understand example to illustrate the power of transactions. Most developers should be able to look beyond that simplification and see how they can put transactions to work (or see that they are unnecessary).