I think the IEO has various advantages, especially in terms of exchange listings compared to ICO, in my opinion, the IEO will have a good future because their tokens will stay alive in the market, the possibility of failure will also decrease slightly.
It totally depends on quality of exchanges. There are shit projects and their shit ICOs. There are shit exchanges and their IEOs. Quality of projects/ or exchanges that stay behind ICOs or IEOs is very important, and will mainly identify success of investments.