The general idea of Yotta at the time appears to be sound [1]. Research has shown that prize-linked savings accounts tend to result in people getting and using savings accounts who otherwise would not have done so.
Just make sure to get it from an actual bank or credit union where your account will be directly FDIC or whatever the equivalent for credit unions is insured, instead of going through some fintech company where you account is with the fintech company where they store your money (commingled with other people's money) in a (hopefully insured!) bank but as far as the bank is concerned its all the fintech's money and you have no relationship with the bank.
Just make sure to get it from an actual bank or credit union where your account will be directly FDIC or whatever the equivalent for credit unions is insured, instead of going through some fintech company where you account is with the fintech company where they store your money (commingled with other people's money) in a (hopefully insured!) bank but as far as the bank is concerned its all the fintech's money and you have no relationship with the bank.
https://en.wikipedia.org/wiki/Prize-linked_savings_account