Even all that exchanger you mentions is popular if the the team really wants to scam there investors there is no guarantee that. But atleast the risk is not that too much unlike the ICO that the team scammer are easily can take money without any expenses like listing in exchangers. A few years ago there is also a initial coin selling in exchangers like IEO today but still after the coin selling the coin is already dump to 1 sat until no ones buy it.