Version question

hello, is recently version 11 able to customize standard field, by customize i mean maybe in a specific country they don’t use some standard field and i need just to remove the mandatory option (uncheck it), but when i do that, it doesn’t allow me because it’s a standard field on version 11, meanwhile in version 9, i was able to uncheck mandatory field on standard fields
any clear explanation on why it has changed ? or if it can be applicable on version 11?