For DeFi the most important thing is liquidity. The more people use the DeFi projects the higher liquidity it has.
To provide best liquidity promotion is necessary and a good conditions to liquidity providers to attract more funds to liquidity pools.
Now DeFi actively hacked and many people are looking for the most safest DeFi protocols.
But now it is difficult to say what DeFi protocol is the safest because many DeFi protocols was hacked.