It's not so safe as you said and most of the safest IEOs are running on the trusted exchange site only and as you can see that about so many bad IEOs even running on the various exchange site. You can't say if all of IEOs were safe but what you can say to tell other if IEO that runs on a big exchange site will give more guarantee than IEO that runs on a little exchange site.
But, analyzation is always needed to be caused by so many IEOs are not giving good result.
What's safe anyway? Putting money on an exchange is one of the least safest ways you can store cryptocurrency these days, I mean, even a big one like Binance that is supposedly super secure got hacked. And we don't even know for sure if these are really hacks or simply just insider jobs.
And worse? These are the ones we know about. I bet you some are hiding their hacks.