If your apartment or rental home is robbed or the apartment above you has a fire and the water used to extinguish it floods your apartment, your landlord's policy won't pay to replace any of your stuff. That's up to you.
You have a lot of money invested in your personal property - and it's worth protecting. And remember, as a renter, you could experience a loss due to something you have no control over.
Also, keep in mind your need for liability insurance. Say your buddy trips over the ottoman, falls and then hurts himself. Like it or not, he could sue you for that. Whether or not he wins, fighting that suit could be an expensive nightmare.