I would not call all of them the same because they are here because they are an improvement to the previous one. IEO are exchange hosted ICO while STO are ICO/IEO that provides the profit as dividend directly to the holders. So, they are not all the same.
The user experience has improved a lot from ICO to IEO and we would see more improvements on experience and security in the future.
After the IEO was launched, ICO projects in this market were no longer interested and it is likely that ICO will soon die this year because IEO has more advantages for investors. I think liquidity is the most important reason why investors like because they can sell the day after the project ends and if listed at a large exchange, their chances of earning a profit will higher than other normal projects. Now Binance, Huobi are 2 exchanges that provide the best projects but the participation rate will be very low