I would not say that IEO sale guarantees that the user will easily and quickly invest. Care is always needed because the projects themselves are not always ready to provide good service, saying we are IEO token. I am watching a project that has been delaying sales for several months. Good startup are able to find investors in any case.
It's good when the exchanges allow you to use ethereum or bitcoin to buy IEO tokens. But when an investor first needs to own the tokens of the exchange itself, this discourages the desire to invest. I understand that such a policy of exchanges is necessary for them to support their work, but all the same, the sensations are not too pleasant from such an attitude.
IEO allows a token issuer to post sales without wasting resources and time. But the real benefit is to token buyers, who dont need to worry about their data or funds being stolen. They just need a verified account on our exchange.