: Beyond funds, these files contain transaction histories and public addresses, which can lead to a total loss of financial privacy. How to Protect Your Wallet
If a hacker downloads an wallet.dat file, they can simply swap it into their own Bitcoin Core folder and spend the balance immediately. The Evolution of the "Hunt" Index-of-bitcoin-wallet-dat
Because this file contains the actual keys, losing it—or having it stolen—is equivalent to losing physical cash. There is no "reset" button or central authority to restore access once the file is gone or its contents are compromised. The Danger of Indexing : Beyond funds, these files contain transaction histories