Unlike a dedicated password manager (such as Bitwarden, 1Password, or KeePass), a .txt file offers zero encryption. Anyone who gains access to your file system—whether through malware, a misplaced USB drive, or a shared cloud folder—can open it with Notepad and read every credential instantly.
If a hacker gains remote access to your PC via a trojan, they don't need to "crack" anything. They just copy the file. Url.Login.Password.txt