DeFi will continue but their trend will end in the next few years. Crypto will always be innovating all the time. Developers will always find interesting ideas for future Crypto developments. Nobody knows how Crypto will develop in the future but DeFi won't end.
How sure you are that Defi won't end? We do not hold tomorrow and we don't know how far defi will run. But if it has a good foundation and development maybe it will last long in crypto space.