Lending ETH on Aave protocol

Am I missing something?

I did some research on the Aave protocol and it appears as if I can lend my ETH, earn interest reward ETH, and withdraw all of it whenever I want.

Isn’t this a great way to add to your ETH stash and potentially earn money?

It seems too good to be true. Or maybe there is some downfall of this venture that I am missing?

I read the Aave rules on lending and I believe I understand everything I need to.