That's why you need to be more selective for what project do you invest.
Remember cryptocurrency is high risk high reward activity so make sure that you have prepare to loss and consider profit as the bonus.
Scammer is just like criminal that looking for the profit !
With every new bug being spotted in the cyber security of the technology you choose, the security is further tightened. For example Bitcoin is very secure because of the blockchain technology. But scamming is not something new in the market.
It has been there since the start and even still the technology is operating with people investing in different projects and holding them for long. The probability of hacking a wallet having coins is very low, almost less than 0.1% in case of blockchain technology.