If you live in the US, not participating in the banking system and not having a bank account is not a thing that you can do, except for religious reasons. From the moment you're born, you're on half a dozen companies' radars for credit reporting and scoring purposes, and most of the major purchases that you need to make to survive require a bank account with a good balance and a good credit score.
> An estimated 4.5 percent of U.S. households (approximately 5.9 million) were “unbanked” in 2021, meaning that no one in the household had a checking or savings account at a bank or credit union.
