OK while I am a big fan of multiple bank accounts (I have three, all for different purposes) this advice is total overkill and inappropriate for anyone who isn't financially stable, which unfortunately, is half of Americans. Two different countries? No thanks, I'm not screwing with that nightmare. I'd like to keep my money in the form of US dollars, I have no need for foreign currency and I don't want to waste money converting to and from different currencies. Most people that I know lack the discipline to manage multiple accounts at multiple institutions.
Credit cards are great for some but inappropriate for others who lack discipline or funds. Keep in mind you spend more when using plastic over cash as well. [1]
No advice is one sized fits all.
[1] https://www.nerdwallet.com/blog/credit-cards/credit-cards-ma...