I think that the ICO project burns unsold tokens, which helps to maintain the value of the token, rather than flooding it, causing the price of the currency to plummet.
In the RIPAEXA project in August, the team burned 5 million XPX tokens to ensure that the participating investors made a profit. Now the project is still in the crowdfunding stage.
https://tec.ripaex.io/If a project development team can see the opportunity, an unsold token they can make a bonus each week for the hodlers.