You have to transfer your assets to their system to lend or staking to get attractive rewards.
Problem: you lose all control of your assets and they can use your assets for illegal purposes
or when their system is hacked you will lose all your assets
or they can prevent you from pulling your assets out of their system.
You should stay away from such forms of defi.
Do not hand over all assets to someone else to manage, no matter who that person is or any organization.
The recent collapse of some defi platforms can be a very sophisticated form of fraud, stealing customers' assets and blaming the market and no one has to be punished by law.