Why? If you have the money to pay the cards off every month, then you have zero reason to have a credit card, let alone two.
A credit card is virtually essential for foreign travel (once foreign travel is allowed again).
1) Its almost impossible to hire a car abroad without one.
2) Hotels will want a large cash deposit if you don't check-in with a credit card.
3) Providing you have the correct card it's much cheaper to withdraw foreign cash from a hole in the wall on a CC than any other card. Much better exchange rate and no forex loading.
I wouldn't travel abroad without two - preferably one Mastercard and one Visa. Some countries (Japan IME) don't widely accept one or the other. If one is rejected/cloned then you still stand a chance of not being stranded in the middle of nowhere.
Having said that, I've just had to tell Santander to shove their Zero card where the sun don't shine so I am on the lookout for another.