Yes you will get more frees, however you shouldn't drop a subject just for the frees.
However if it is giving you a stressful time then by all means drop it if it means you won't be able to do as well in your other, actually relevant subjects.
Additionally, it depends on the policy of your school, some are chill with you just dropping to 3, others may expect you to pick up another subject, or show that you will do better in another subject, see your head of 6th form.