Escrow on ICOs? I think its not possible not unless you are talking about signature/bounty campaign. Its still hard to avoid scam ICOs because even they have escrowed bounty campaign they still failed on their project after that, so your money will be loss for good. There is still no guaranteed profit when you invest on ICO, for me its better to buy token after listing on the exchange where token is more cheaper than the ICO price.
It is very possible and there were many icos in the past that used escrows, and in a way I agree with the OP, if we really want to avoid most of the scam icos in the market you need to invest only on icos that use escrows that are independent from the developer team and that are trusted by the community, that way if something goes wrong the escrows are going to protect the investors.