They're definitely not useful for proper investment decisions, but they can be a good idea to learn something about what's going on. Sort of like, just to catch up with what's out there.
Mainly because they're paid to list those reviews, if they're not paid then they're posting those reviews to earn bounties. So either way, you know they're saying something good, or can't say something too bad, or they won't get paid or not get enough bounties.
They're ok for finding websites, channels, etc. But nothing you can't find on your own.
I agree with your suggestion because these sites to me are only good to get updates about new projects and their ranking cannot be trusted because most of them paid to give good scores to a project that does not even worth it while less ranked projects even do better. When you check the rating of the project, it is good for you to sit back and do your own research before you put your money in it.
Definitely! I mean, think about it. If these sites were all honest and objective, then in general most of the ratings would be low. Because a good-rated ICO is very hard to come by. It's not just about the team and advisers who are all good and well known. It's not just about a great whitepaper, cause everyone can write a decent one these days and charge a few hundred dollars.
In the end, it's very hard to rate an ICO until they have a good history of product development and active developers - which 99% of ICOs don't have.