ICO was never a guarantee of project being successful because ICO means only raising funds for any project.
In fact other things played a part in success like good exchange listing, promotion and hype, good marketmakers, partnerships, marketing of project, raising only required amount of funds, having a working product and real concept based project etc. For a real success you need to keep balance of everything and success does not mean 10x on listing and later dump.
Some projects have no ICO and they are backed by VCs and for community they announce some airdrop to get more people in community. So that can be also good way to go.
But success only comes with how you manage your project and what are your strategies for short term and long term.
even the crowdfund are raised much money, but still make the project are failed and in other case after ended ICO and raised enough the product they offered are useless or still don't like ecpectation from ICO campaign, between their product offered in ICO and after released are useless