Over time, available niches will become less and less available. Therefore, the number of ICOs and related programs will be reduced. However, their number will remain quite large. In this case, the requirements for participants will increase all the time due to the increase in professional bounty and airdrop hunters.
A good project always provides a product or a service which can be useful for everyone. Blockchain helps to facilitate the use and improve the quality of a number of project's features. It does not matter whether a niche is occupied or not. The competition will make things right.