There value will surely dropped based on the numbers of these so-called DEFI projects are being pumped into cryptos market, taking a cursory look at the bounty section of the forum, there are many of them popping out daily, however some of the projects might survive based the bullish outlook of the market presently, meanwhile some investors are always selective in DeFi projects.
I agree that the future of the projects depends too much from the future of the cryptocurrency market. If cryptocurrency market will raise it will be much more simple to survive to many projects. People will continue to buy tokens hoping that their price will raise in future. Now many Defi projects use staking system to encourage people to hold tokens. Here is an article about staking
https://medium.com/bonfiorg/introducing-bonfi-web-staking-7368467d18ccAnd I think that under any market conditions, a project should be developed if it is really worthwhile.