I think it is time to be careful of Defi projects now because the hype is getting too much and could end badly mostly wit newer projects. About the $5 billion in value, this looks exaggerated because once others or rather newer Defi projects starts coming up in mass, attention will be divided and drawn from already developed ones hence that mark might not be reach; this case scenario depends on if there aren't scam Defi projects. But can one rule out the fact that scammers will likely not develop theirs? No, hence another reason this anticipated value might not be reached.
Indeed! With the hype surrounding DeFi projects, there will be scammers that will use this platform to deceive their investors. As we all have seen, these scammers are getting better in deceiving the community. For now, it is better to stick with the known and established DeFi project like Chainlink. But for newcomers, you have to scrutinize it before jumping on the bandwagon.