That's why setting contracts is never going to be intelligent, too much scamming in there.
Ok, let's see. If I have correctly understood, you are talking about selling contracts instead of bitcoin (for, as long as I can read you are talking just about bitcoin)? What do you exactly mean by that? People buy and sell BTC, yet there are many exchangers in which you don't really own the bitcoin, is that what you meant?
Futures contracts are agreements to buy or sell at the contract expiration date. So, if you buy contracts at $9,000 and hold until expiration at $14,000 you will have profited by $5,000 times the number of contracts you held.
Both the CME and Cboe bitcoin futures are cash-settled contracts, so there is no BTC collateral involved whatsoever. People believe that for this reason, there will be manipulation. In reality, it's difficult to manipulate that way because the collective market can arbitrage the price spread by simultaneously longing futures and shorting spot (or vice versa).
I can't see exactly your point, due to the misuse of the concept of crypto, I believe. Why should I buy a contract instead of a bitcoin by myself? Because of the lower price? But isn't it just a crystal-clear scam?
They're only a scam insofar as all futures markets (or ETFs for that matter) are scams. These markets are intended to track the spot markets. For risk and compliance reasons, many investors/entities cannot or will not participate in BTC spot markets. Futures markets -- and potentially ETFs -- are an avenue for those people to get exposure to the market.