You always have a choice, to participate in ICO or to buy tokens on the exchanges. Sometimes you to buy tokens on exchanges cheaper then ICO price. It depends on the project popularity and many other factors.
The purchase of tokens on the stock exchange after ICO looks even more attractive recently.
You're wrong. This is true for many projects, but not those that are popular. In such projects, even bounty hunters do not sell their tokens, but keep them waiting for further growth.