You are not compelled by law to use it. You may be addicted but it is a different problem. So the short answer is it just you that makes it difficult.
Not everyone is addicted, but rather Facebook has become arguably necessary because of its network effect.
Facebook has become the de facto standard of communication in some institutions. For example, in some universities, important notices on due dates or class cancellations is done solely through Facebook. One may be very heavily pressured to use it.
By the way, I don't have a Facebook account.