Then the SEC went after the ones that were merely flaky. As in [3], or "a blockchain based food review service with in-app purchasing of tokens". This actually got going, not that anybody used it much. They hired a "YouTube influencer" and claimed “199% GAINS on MUN token at ICO price! Sign up for PRE-SALE NOW!”
Along the way, the SEC found some ICOs from the usual suspects in the penny stock market. Those got shut down.
Then they started sending out letters along the lines of "Hello, ICO promoter. What you're doing is probably illegal. Do you want to give the money back now, or do we bring out our big hammer?" This stopped a lot of potential ICOs.
If you haven't seen it, see the SEC's fake ICO site.[3]
I have yet to find an ICO that resulted in a real, operating, profitable business that wasn't some other cryptocurrency/blockchain based thing. We're not seeing ICOs to build factories or farms or do real stuff.
[1] https://www.sec.gov/news/press-release/2017-185-0
[2] https://www.sec.gov/news/press-release/2018-94
[3] https://www.investor.gov/additional-resources/news-alerts/pr...