Many ICOs will fail, it is common even in traditional investing where 95 percent of startups simply fail. In the beginning and in unregulated market percentage of scams is higher though. You must invest knowing that it is gone money, and inves only what you can lose. A lot of them will fail but on those that succeed people gain huge percentages
Yes, that is correct we should invest only spare money on these high-risk investments. But people borrow money from others to invest on these cryptos and that is the biggest mistake we never should do it. If your investment ends up like this one then you lose your money and also need to pay back borrowed money with interest so hit from two sides.