Answer
What if the creator never delivers the reward?
Short answer
The escrow does not cover this, and no crowdfunding platform's does. Once a campaign reaches its goal the money is released to the creator and the refund path closes permanently — so the protection here is against a campaign that fails to fund, not against one that funds and then disappoints.
It is worth being exact about what the guarantee is, because the two failures get confused constantly. The contract has one rule for refunds and one for payouts: a backer can withdraw while the goal has not been met, and the creator can claim only once it has. The moment those cross, the refund instruction stops accepting calls. That is the whole mechanism, and it is deliberately narrow.
So the risk you take when you back a funded campaign is delivery risk, and it is real. The creator may be late, may ship something worse than they described, or may fail entirely — usually because building things is hard rather than because anyone set out to defraud you. This is true on Kickstarter, on Indiegogo and here, and any platform suggesting otherwise is describing a policy rather than a mechanism.
What reduces the risk is what you can check before you pledge. Has this person made something before? Is the goal proportionate to what they are promising? Are the updates specific about problems or only about progress? A campaign that has never mentioned a setback is either extraordinarily lucky or not telling you things. The answer on spotting a scam goes through the signals in more detail.
What we can do after the fact is limited and we would rather say so than imply otherwise. We can remove a campaign, we can refuse a creator a second one, and we can hand what we know to the people whose job that is. What we cannot do is reach into an account we never held the keys to and take money back, which is the same property that stops us doing it to anyone else.