I think this is not a project problem, but a sales system problem from a project. when the IEO gives a positive response to investors, and provides better benefits from ICO, of course ICO will slowly disappear. but, currently there are still a number of potential ICO projects. if this has good results, I think ICO can still survive.
after all there are also several projects that combine both sales systems. some use the ICO and IEO sales system in stages. and I think it all becomes reasonable, because maybe that will make their sales plan get funds from investors maximally. after all, I have not heard of any successful IEOs other than those carried out in exchange with big names.
Good project needs a good platform and marketing strategy to be known and attract investors. Having IEO now helps the team be listed already in an exchange that gisves chance for them to be notice, they will just be needing a solid project that will convince investors to try it.