I'm Really Careful, So I Don't Need Renters Insurance, Right?
You could swaddle yourself in bubble wrap, ban candles, and triple-lock every door, but you'd still need rental insurance. No matter how careful you are, you can't bank on other people taking the same precautions.
Let's flip that fire scenario: now it's your neighbor's fire that damages your apartment. You've done nothing wrong, but everything you own is now ruined.
If you have renters insurance, this is no problem: your policy can cover replacements.
But if you don't? You'll have to sue your neighbor for benefits. And if your neighbor doesn't have insurance, you're unlikely to receive anything at all.