It looks like you are only counting for the scam project but you are not aware if there was a lot of successful icos.
It's better for you to visit this site
https://icodrops.com/ and look at the previous ico list and there was a bunch of successful icos. The future is still really bright.
based on the data from this site it can be seen that the relevance of the ICO has decreased significantly compared to 2016-2017, people’s opinion is interesting whether anyone is following the ICO, or many have switched to IEO ?
They indeed started to disappear within those years although I still managed to join some at year 2018, and there were quite a lot but not really as many as you think that time.
IEO replaced ICOs and don't worry, IEO is still a subset of ICO but they just have different means of how they work such that the project requires to comply to the requirements of the exchange before they get listed.