I've been working in data security and encryption for 20 years. At one point Equifax was using one of the encryption products I designed.
The more up to date recommendation is rather than changing passwords often, just use good ones. Good passwords are long strings of random characters. Or long passphrases. The former are impossible to remember, so you need a password manager. The latter can be remembered but are difficult to type. See the new NIST password recomendations:
NIST’s new password rules – what you need to know – Naked Security
Even better is to use two factor auth. A problem with that is that you need your phone to be working and with you. There are attacks on two factor auth (for example it's possible for attackers to intercept or redirect SMS/MMS messages) so it's not perfect but it's better than even the best passwords.
The Equifax data that was leaked won't include authentication information for your bank etc. accounts. Changing passwords or turning on two factor auth will make it harder for attackers to get into those accounts but won't prevent identity theft. That data is kept in many places (like Equifax) that are not associated with your accounts.