One of my banks uses email two factor auth- if I lost access to the email account and had no accessible backup email set I can see how being locked out of the email account would deny access to the bank account.
Not all banks in all countries do this. One of my banks required me to email my passport, drivers license, and case number to the person I was talking to over the phone in order to prove my identity.
My passport was 1000 miles away. My drivers license was expired (was living in NYC at the time, and not driving). My bank had no physical branches outside of the state of Louisiana.
All of this after answering the security question, and providing my SSN. How I eventually was able to re-enable my account was calling a friend who worked in the mortgage department to have my account reset. If I didn't have a friend at the bank, I wouldn't have been able to reset my account without flying either back to NYC or having a family member drive me from Texas to Louisiana.
The BBC has edited the article and the line I quoted I can no longer find. I was pretty sure that particular person the quote was from was described as living in the US (as is another one of the examples in the article).
One of the other individuals in the article lives in Saudi Arabia, which has a very highly developed banking system.
Well, if you truly cannot operate without access to your email account should also have a game plan for if you forget your password to your email and cannot access your email account.