Aave V4's Reinvestment Module doesn't seem particularly impressive. From what I've seen, it essentially reinvests idle funds in the lending market that haven't been borrowed by borrowers. I have several questions. What happens if too much is taken? What happens when lenders want to withdraw and the pool's buffer isn't enough? This raises redemption issues. If it affects borrowers, it's inappropriate; taking too much is clearly bad. But if it's too little, the increase in returns is limited. Furthermore, this introduces another risky party. According to official calculations, in 2025, there will be an average of approximately $1.2 billion in idle USDT. Investing all of this would increase lender returns from about 4% to 4.9%, but obviously, it's impossible to invest it all. Even after halving it, the increase in returns would probably be around 0.5%. Aave's explanation is that this ensures, in most cases, lender returns are not lower than short-term risk-free rates like SOFR. It's mainly for dealing with market downturns. Overall, it's at best a nice-to-have feature.

The V4 still doesn't feel as good as the Morpho.

I don't know. Morpho is great, but it doesn't make money, which is a bit of a pain.