In my opinion, I think investing in ICOs is way better than investing in a coin that is already listed on exchanges. Though there is risk involved, but the chances of you not gaining profit are very slim. When you invest in an ICO, you buy your tokens at a very low price including bonuses, which further means that if you hold your coins for long term, my might gain more than 1000% profit from the initial investment.
I think it depends as you can see in same cases that coin after getting on exchange is going under ICO price, so yes it could be better but you really need to choose carefully, the best ICO are ones which are hyped without bounty so nobody will mindlessly dump it on exchange.