Whether or not you "believe" raffles/lotteries to be a useful system does not change the fact that it was a system with a $280BN market cap in 2015. Lotteries on a blockchain with smart contracts solve three problems with traditional lotteries: transparency (provable fairness), easy and secure participation, easy and secure disbursement.
We'll surely see them.
Yes! You can see them right now. There are thousands of DApps, at different stages of development[2].