Hmmm, I think it'll be very difficult for ICO just because of STO. As I can see STO is becoming a hot trend because when an investor invested money in a STO, he will be given Security Token which also mean share of project behind STO but with ICO, we just can buy token to help project successful but there is no way that we can have share from these projects.
It's all about modification from ICO to STO, and this changes will help to minimize from scam projects which are affecting crypto's credibility. May investors will choose into in ICO again if there will be no scam issues and they'll found out that there is a reason to believe on it again. Just like turning of token sudden drops which is below the ICO price and they could get guarantee of not losing their funds.