The main reason I carry multiple cards, and Cash was because my debit card was used for fraud once, which shut down my card, and it took several days to get a new one.

Now days they can print you a new card in real time at the branch, but still I will never not have cash, and not have a backup card

I also NEVER use by debit card for anything other than ATM now, credit cards and pay it off every month... I dont even carry my debit card anymore, it is locked in the safe, and a bring it out when I need to get more cash.