Nothing last forever, falling apart is a certainty of cause, you can't expect DeFi projects to keep taking the first in crypto space, there is time for everything but I just think that DeFi reign will last longer than that of ICO projects.
I agree with you, and there is nothing last forever because with the emergence of an alternative system and this system has achieved successes, So the investors automatically turn to it despite its risks, and the hype turns to it, and it becomes the talk of the people. any DeFi project or other may fail if this project does not have an expert team in its management But with time, if this project does not achieve its goals, it is better to leave it.
DeFi is still evolving and they are getting a lot of fo supports from investors and the community this is why the network is clogging because of to many transactions in the DeFi projects, I guess they are going to be part of the future of Cryptocurrency unless we see major hacks in the smart contract of this DeFi projects.