Maybe this is not the case outside the USA but in America, I have never seen any in-person merchant that does not accept Discover. The only online merchant I know of and regularly buy from that doesn’t take Discover is TCGPlayer, but it is trivial to get around this by using PayPal.
Discover cards are also multi-network and can also be processed as Diner’s Club International or JCB in some countries. This matters more internationally, of course, but it is an option.
Maybe this is not the case outside the USA but in America, I have never seen any in-person merchant that does not accept Discover. The only online merchant I know of and regularly buy from that doesn’t take Discover is TCGPlayer, but it is trivial to get around this by using PayPal.
Discover cards are also multi-network and can also be processed as Diner’s Club International or JCB in some countries. This matters more internationally, of course, but it is an option.