You don't need to use your account. Not viewing ads hurts them enough and if you don't login they can't count you as an active user. The overall number of users

You don't need to use your account. Not viewing ads hurts them enough and if you don't login they can't count you as an active user. The overall number of users is unimportant anyway and they won't delete your data, so no reason to deactivate the account.