Buying coins when the price is low at ICO is indeed advantageous because the developers give a lot of discounts of up to 40% to investors, but when you choose the wrong altcoin, I mean after hardcap is reached, this is where investors will wait for the coin to be registered in a good exchange or not.
From the development of the current investment model, everyone can choose altcoin by following the IEO because developers sometimes lock tokens when they see a low buy volume to avoid a dump.