As an investor, i cannot participate in IEO conducted by small and new exchanges. The main reason why IEOs are preferred to ICOs is because they are more prone to scam than ICOs, and this is because the exchange validates its legality with their reputation. Imagine Binance or any top exchange conducting a scam project, it will jeopardize their integrity, and these exchanges do not want their integrity in question, so they only offer legit and promising projects IEO. New exchanges do not have the reputation to validate a project, they are just after the profit, SO they might promote a scam project either intentionally or unintentionally.
But even Binance has been forced to delist coins whose developers dropped the project or ceased to be interesting for investors, which means that even the support of a highly prestigious exchange is not an infallible guarantee that this or that project will have great success in the long term, that is why it does not matter who endorses or sponsors an IEO, we should always be aware that the possibilities of suffering losses are inherent to this type of investment, so even when investing in Binance only we must invest the capital that we can afford to lose.