Take Cult of the Lamb (early builds used ES3). Some players reported success editing gold and devotion using online ES3 editors. However, updates introduced obfuscation, and the editor failed to parse the file correctly. Online tools are thus a —they work only for unencrypted, uncompressed, and simply structured ES3 files from static game versions.
This means the file is encrypted or saved in a raw binary format. An online editor cannot process this unless you find the decryption key hidden within the game's source code using tools like IL2CPP inspectors or AssetRipper. The Game Resets My Progress After Editing