Reputable repackers (like FitGirl or DODI) provide compression that is safe and verified, though it will still be larger than 686 MB to ensure the game actually works.
"Resident Evil 4 is a highly acclaimed survival horror game that has been compressed to a remarkably small size of 686 MB for PC. This version, often referred to as a 'highly compressed' or 'lite' version, is ideal for users with limited storage space or slower internet connections. Despite its reduced size, the game retains much of its original quality, offering an intense gaming experience.
Before proceeding with the download, ensure you have sufficient disk space and that your computer meets the minimum system requirements to run the game smoothly."