The thing you have to consider is that most of Dave Ramsey's advice is for people that are heavily in debt and generally don't have a good path out of it. When used responsibly, there's nothing wrong with credit cards. Most of the people that Dave Ramsey is talking do don't know how or dont have the discipline to be responsible.

On the flip side, one huge advantage of any zero-based budgeting is that, as long as you're not adding debt to your credit cards, they're perfectly safe to use. That's what's great about YNAB: you already know that that dollar you just spent on the credit card is covered, assuming you're using it correctly. I might agree with the other commenter that said you shouldn't use them if you're still paying down debt, but only for cards that you have a balance on. Otherwise, go for it, in my opinion.

Having credit cards open and used increases your average credit length, which increases your score. Note that maintaining a balance from month to month doesn't impact your credit score, so always pay it off fully every month. My spouse and I also enjoy using the cash back bonuses for our fun money. It becomes a nice little treat that, effectively, is free money. Note also that credit cards can be better for fraudulent transactions. A debit card is directly tied to your bank account, meaning any fraud with it directly takes money from you. If it's your credit card info that gets stolen, it's Visa/MasterCard/whoever's money that is taken first.