Just build your site and worry about the traffic later. What matters is to make your service better and put a splash of originality even though it is a copy a other established ICO listing websites.
You dont have to reinvent the wheel to start something new.
If you have the coding knowledge then start coding if not just hire a developer. Don't think about the traffic and profit for the meanwhile, you have to build your reputation and many other things as stated above to make your website popular.
And when it's already set, advertisers will just come.
The OP has no problem on the traffic, it is the type of website he is referring to when he created this topic.
i have a big community in crypto, so i get traffic from there.
Also, he's generally asking if people would still be interested on ICO listing sites (not the technical aspect of making it).