when we talkin about IEO we must searching about exchange or market which bring IEO's Project, The project will be trusted when listed on good exchange...
We (Me or you or everyone) have also done this method (searching information) during the ICO and STO periods before the hype IEO come. in my opinion it does not depend on the place of exchange (binance or other), but depending the scale of the project is useful or not for the future.
if the project *only* looks like legit/trusted because it does an IEO on binance, I think this mindset is completely wrong. Investing is okay, but we don't know further about the price after it is available for trading, there is no guarantee that prices will be the same when investing. can fall very deep or up high. but I'm sure the price will fall.
...and of course scammer will always make new inovation to join this chance, so, be carefull!
as you said, many projects now start various ways to do the IEO. Scammers have many ways to get money. so 100% i agree with you!