I honestly don’t think I’m overeacting… the potential is there to make a right mess of a holiday for the sake of very little outlay.
Given the option of forgoing features such as location based security, ability to freeze card, ability to enable/disable magstripe at will, instant transaction notifications… against using a cheap/old/second-hand/borrowed/found in back of draw smartphone with local data SIM and keeping those features, I think I’d choose the latter.
There are very few places in this world where I’d find myself without data/wifi at least once every 24 hours, and if I were in such a place it’s likely that I’d find little use for my card anyway. For my own piece of mind I would want to be able to keep a regular eye on my account and Monzo offers me the most convenient way to do that.
I’m not suggesting that what’s good for me is right for everyone, rather pointing out some of the obvious things that should be considered when travelling abroad without the app at hand.