Do flash loans move the funds to your wallet or allow the lender to control your wallet?

I'm reading a new article which says:

https://www.theregister.com/2022/04/18/beanstalk_loses_182m_flash_loan/

"Hackers like to use the flash loan since they don't even have to risk their own capital, and the wallets don't get traced back to them, since they are using someone else's funds," Check Point security researchers noted in March. Last year another DeFi platform, CREAM Finance, lost at least $18 million in cryptocurrency in a flash-loan attack.

I thought flash loans put the money into your wallet. But in the news article above it says they can't be traced because the aren't using their own wallets. Won't that mean the loan involves controlling some else's wallet?

And what are the legitimate uses of flash loans beyond using the extra tokens to cast votes in a DAO?