While ICO raises money for a project, it also builds liquidity for the project before it's listed as a tradable asset on exchanges.

That's very true about using ICO to build liquidity for the project, a proportion of the funds received in the ICO is added to the liquidity pool to ensure easy exchange of the token when listed.

Many new crypto projects created by scammers are a ploy to lure investors to buy into the project.

This is one of the most relevant disadvantages of ICO because some of them have no good intentions rather than to steal investors funds and since there is no regulation, it leads to loss for the investors.