I can think of a number of reasons why people might have more than one email address and most of them are legitimate, but I've often wondered how many people really do have them. They are easy to get and can be useful as an alternative in case of a spam attack.
However, some people use the "other" account as a secret, especially from their spouse or partner.
Don't worry about Google or Apple tracking your location. Get over it if you're nervous hackers may access your voice mail. It's actually the one you love that's most likely to be snooping through your email and cellphone history.