Definitely the era of ICO in its original form is coming to an end. Now there are better alternatives, such as IEO, STO. Investors like IEO more, because the sale of tokens takes place on the cryptocurrency exchange, which means that this token will be tradable on the exchange. The STO model is preferable in that the tokens fall under the regulation of some legislation. This in turn causes more confidence among investors.
ICO's will come back again because most people are used to them. There is a lot of growth within the IEO world of course.