The cost of running the rewards scheme must be paid. It is like a tax you incur. Also the cost for you to participate can be substantial in the form of time/attention. All for 1%-2% rebate.
Many rewards programs are also predatory in the way they want to sell your data so you are targeted by advertisers for products you wouldn't buy otherwise.
Many rewards programs are also predatory in the way they want to sell your data so you are targeted by advertisers for products you wouldn't buy otherwise.