The reason they get hacked is because its new technology and full of bugs. Hence why there is usually a "bug bounty" for many projects where the hacker can just legally get paid for his "bug finding" rather than exploit the bug and take 100% of the assets.
Hence why you shouldn't keep large amounts on anything Defi related. Keep it cold storage and when you want to actually trade, then send the funds and when you are done send them right back. Keep everything in Ethereum COLD storage.
But we know that these back testing are done by the team itself and not on some launching some bug bounty or some sort which it would really be ending up on having that huge risks of exploits on the
time that they would really be opening their doors.They'll soon realize about the bug but its already too late and the damage has been done. Speaking about exploits not only limited on DeFi
then its not really that something new.We know that this place is a honeypot for scammers,hackers,swindlers and other similar fellas who does have those
kind of intents.This is why its something inevitable where losing huge funds in relation is really that common.