In the most basic sense, I think ICOs are alive today.
But, more figuratively, I think they are dead. (Or should die soon?)
The best kept secret about ICOs is that they are fundamentally centralized. An entity is actually selling you the crypto. One single entity. And, in most cases (though not all), that crypto is not yet developed. Instead, they have a placeholder ERC20 token.
I'm not a huge fan of law and legislation, but I have to say: if you are buying a token that is a promise for something that is supposed to be valuable in the future, that feels a lot like a security.
And finally, it's important to mention that Satoshi never did any kind of ICO. Instead, Satoshi made bitcoin work (with the help of an amazing community), and then simply released it. That, to me, is how decentralization should work.