> Although the council had planned to implement Oracle "out-of-the-box," it created several customizations including a banking reconciliation system that failed to function properly. The council struggled to understand its cash position and was unable to produce auditable accounts. It has spent more than £5 million on manual workaround labor.

Not a great example of a single centralised system. The errors came from trying to write custom reconciliation code between two systems, the ERP and the bank - perfect example of the problems OP raises.

Fair point but AWS is also highly extensible, and i'm not sure about Palantir but i guess it must be too to a point? Maybe it's a classic case of good abstractions vs bad ones