When you develop large flows with many actions it is difficult to collect failures from each action that could potentially fail.
It is possible to collect the details from each potentially failing action howeever that will very quickly create an unwanted mess.
It would really help if there was a error() function giving an array of all failures of that flow run, so that this function can be used to report the failure back to the user. At the moment the only thing we've got is the workflow() function that can be used to generate the flow run url. The end user however should not need to look at the complex flow run.
Also the user may not have access to the flow run.