When I travelled a lot for work. I used to take 6 cards with me. Two visa debits (either Halifax or HSBC plus NatWest) and four credits, Visa, MasterCard, a corporate Amex and Diners Club (ok, technically a charge card
).
I always told my providers when I was travelling, either via phone or app. However that didn't stop them regularly (probably 40% of the time) stopping my debit cards on first use in a foreign country.
I can think of at least two occasions (Hong Kong and Brazil) where I would have been completely donald ducked without the credit cards to hand, when one debit card was blocked on first use, and the other one eaten entirely by a different atm. As LC0112G points out, no one card provider is universal, something I only found out after my trip to Brazil, where basically no-one accepts VISA.
No such thing as a free lunch
I'm well aware that my freebies are funded by other users' monthly interest payments, which is why, like any other tool, credit cards should be used properly. They do have benefits that other payment methods don't, but also plenty of opportunity to get yourself in a mess. Caveat emptor and all that jazz.