I have been in the US for two weeks and in many places magstripe is the preferred method of dealing with cards. When using it for the first time it was rejected and I asked the cashier to wait a second until I enable it. I did.
But now the magstripe works all the time even though it’s disabled in the app. I didn’t mind it as I forgot to enable again and was in places where they didn’t have chip&pin nor contactless but I think it would be a good idea to check if everything is working correctly in that department.
Not sure why it’s ‘bad’ per se. It’s Monzo taking this risk, not us. It’s a calculated risk. The toggle was only ever advertised to disable ATM use.
P.S. to clarify, Monzo is taking the risk of having to clean up the mess which costs time and therefore money. The actual transaction amount financial risk is borne by the merchants in, I believe, every region now (Israel was very recent but I think with Israel now being covered by a liability shift it’s every region).