Well, it can be called a kind of paradox. Of course, there are projects that manage to conduct IEO for free, they pay part of their coins to the exchange. But as a rule, there is no trading volume on such exchanges.
If the project manage to conduct IEO for free and pay tokens to exchange usualy it is not a good exchange and it is very difficult to collect money during IEO and usualy after IEO when the listing starts the price of the tokens falls and tokens becomes shitcoins.
I don’t even argue! But you understand that in order to at least somehow draw the attention of the cryptocurrency community to the project, listing is necessary. And carrying out IEO already automatically implies that the coin of the project will be placed on the exchange.