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.
Agreed with you, even some ICO's have escrowed their bounty campaign, we still didn't know if it would be a scam after they finish their ICO. And Some other ICO's still turned into a scam even their project is successfully ended. And some ICO's successfully ended but when listing on an exchanger their value is so low and not even met their ICO price.
Anyone can just start a smart contract and have some tokens generated but that does not stop them from being scams, so it is not just about escrowing the tokens. One thing that is essential when it comes to ICOs is to just make sure you do a very good due diligence on the team, their competence, their past achievements and then look at the present moment and the possibility of them achieving what they are stating and above all, you really do not want to leave out the product availability as that is the main essential thing and not just some empty promises.
Even if I like the team and they are all just about empty promises, I would prefer to just chill, hit the exchange, keep monitoring their progress and when I see they have been able to come up with something realistic and tangible, then, they will earn my full trust.