Now things have almost changed with the many new concepts that have been introduced into the crypto space. So that concepts like ICO no longer exist in the new campaign and the team has changed and replaced it for a better one like the current IDO.
In 2017 there were indeed many unique events that could serve as the experience of everyone who had been in crypto at that time.
It is not really that much "changed", the idea is the same, you pay some people to buy their project from them and they make money and you hope that you will get some profit out of that while they are guaranteed to make money, and you hope that they will use that money to make the project better.
There is zero decentralization, they just give you something and you look up to them to make something with that money. Did we pay satoshi to do bitcoin? Did we pay eth? We just let them happen and they grew organically, same with ltc, or monero or any of the old ones. To this day all the new projects asks you to give them money and that is the biggest problem.