Almost any hardware item you buy from us has a brass/bronze substrate, that is to say that it is made from brass or alloy composed mainly of copper – with tin for bronze and zinc for brass.
This means your hardware is built essentially to last for many generations. It can’t rust or deteriorate, other than with a steel based product which should be treated differently externally. What will happen is what you would expect if it is badly treated or neglected.
Atmospherics impact on how hardware looks over time, best explained by considering how your car would look if left without washing and basic car maintenance. Exterior hardware with minimal car will look good long term with this care.
A regular wash with a solution made up of two litres of water quarter to a cup of vinegar and a dash of dishwashing detergent. Clean with a cloth, rinse with fresh water and use a chamois to finish off.
This regime will guarantee your exterior hardware will stay looking good no matter which finish, raw, unlacquered brass, bronze and any electroplated finish.