there is a clear distinction between ICOs and STOs. ICOs are scammed by greedy scammers who want to make quick money with other people's money. It is definitely performing well than normal token sales.
Honestly, one should not really be comparing them, if not for the scammers that came to destroy the image of ICO, take scammers out, ICO is by far better than them, ICOs gives chances to people without strict policies than these ones, if you dont have the opportunity to participate in ICO presale, you have the chance to wait for the coin to get listed and participate after presale.
If we look at STO and IEO, they both limit people, if you dont have money, you get no chance to participate at all, IEO only consider presales and no post sales, while STO is too stingy of a system with their low meaningless amount that tops up an investment after a long term.