The single best way to protect yourself against airline screwups is to make more than one flight booking to get where you are going. And doing this has been made easier and less costly by changes to airline policies over the past two years.
When your flight is delayed and you’re going to misconnect, or your flight is cancelled, other flights ae often too full – your airline may not be able to re-accommodate you quickly or even for several days. But is already having a backup flight in case – taking a seat you may not intend to use, that the airline cannot sell and other passengers can’t use until you give it up – ethical?